Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf ·...

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Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk LSV Cachan / University of Warsaw Wednesday, November 18, 2009

Transcript of Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf ·...

Page 1: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Deciding Emptiness of min-automata

Szymon Toruńczykjoint work with

Mikołaj Bojańczyk

LSV Cachan / University of Warsaw

Wednesday, November 18, 2009

Page 2: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞Wednesday, November 18, 2009

Page 3: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞Wednesday, November 18, 2009

Page 4: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞Wednesday, November 18, 2009

Page 5: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞Wednesday, November 18, 2009

Page 6: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞Wednesday, November 18, 2009

Page 7: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞Wednesday, November 18, 2009

Page 8: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞Wednesday, November 18, 2009

Page 9: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞Wednesday, November 18, 2009

Page 10: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...

Wednesday, November 18, 2009

Page 11: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...cdz

Wednesday, November 18, 2009

Page 12: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

cdz

Wednesday, November 18, 2009

Page 13: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

100

cdz

Wednesday, November 18, 2009

Page 14: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

100

200

cdz

Wednesday, November 18, 2009

Page 15: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

100

200

300

cdz

Wednesday, November 18, 2009

Page 16: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

100

200

300

030

cdz

Wednesday, November 18, 2009

Page 17: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

100

200

300

030

130

cdz

Wednesday, November 18, 2009

Page 18: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

100

200

300

030

130

010

cdz

Wednesday, November 18, 2009

Page 19: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

100

200

300

030

130

010

110

cdz

Wednesday, November 18, 2009

Page 20: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

100

200

300

030

130

010

110

cdz

210

Wednesday, November 18, 2009

Page 21: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

“c tends to ∞”

liminf(c) = ∞

deterministic automata with counterstransitions invoke counter operations:

c:=min(d,e)

c:=c+1

acceptance condition is a boolean combination of:

Min-automata

Example. L = {an1 b an2 b an3 b...: n1,n2... does not converge to ∞}Min-automaton has one state and three counters: c,d,z-when reading a, do c:=c+1-when reading b, do d:=min(c,c); c:=min(z,z)

Acceptance condition: ¬ liminf(c) = ∞ ∧¬ liminf(d) = ∞

a a a b a b a a b...000

100

200

300

030

130

010

110

cdz

210

020

Wednesday, November 18, 2009

Page 22: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Max-automata

Logic

Wednesday, November 18, 2009

Page 23: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Extension of WMSO by the quanti$er

Max-automata

Logic

Wednesday, November 18, 2009

Page 24: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Extension of WMSO by the quanti$erUX φ(X)

„there exist arbitrarily large ( "nite) sets X, satisfying φ(X)”

which says

Max-automata

Logic

Wednesday, November 18, 2009

Page 25: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Extension of WMSO by the quanti$er

Language: {an1 b an2 b an3 b... : n1 n2 n3... is unbounded}

UX φ(X)

„there exist arbitrarily large ( "nite) sets X, satisfying φ(X)”

which says

Max-automata

Logic

Wednesday, November 18, 2009

Page 26: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Extension of WMSO by the quanti$er

Language: {an1 b an2 b an3 b... : n1 n2 n3... is unbounded}

UX “X is a block of a’s”

UX φ(X)

„there exist arbitrarily large ( "nite) sets X, satisfying φ(X)”

which says

Max-automata

Logic

Wednesday, November 18, 2009

Page 27: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Extension of WMSO by the quanti$er

Language: {an1 b an2 b an3 b... : n1 n2 n3... is unbounded}

UX “X is a block of a’s”

UX φ(X)

„there exist arbitrarily large ( "nite) sets X, satisfying φ(X)”

which says

Max-automata Min-automata

Logic

Wednesday, November 18, 2009

Page 28: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Extension of WMSO by the quanti$er

Language: {an1 b an2 b an3 b... : n1 n2 n3... is unbounded}

UX “X is a block of a’s”

UX φ(X)

„there exist arbitrarily large ( "nite) sets X, satisfying φ(X)”

which says

Max-automata Min-automata

RX φ(X)

Logic

Wednesday, November 18, 2009

Page 29: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Extension of WMSO by the quanti$er

Language: {an1 b an2 b an3 b... : n1 n2 n3... is unbounded}

UX “X is a block of a’s”

UX φ(X) which says

Max-automata Min-automata

RX φ(X)

„there exist in"nitely many sets X of same size, satisfying φ(X)”

Logic

Wednesday, November 18, 2009

Page 30: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Extension of WMSO by the quanti$er

UX “X is a block of a’s”

UX φ(X) which says

Max-automata Min-automata

RX φ(X)

„there exist in"nitely many sets X of same size, satisfying φ(X)”

Language: {an1 b an2 b an3 b... : n1 n2 n3... converges to ∞}

Logic

Wednesday, November 18, 2009

Page 31: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Extension of WMSO by the quanti$erUX φ(X)

which says

Max-automata Min-automata

RX φ(X)

„there exist in"nitely many sets X of same size, satisfying φ(X)”

Language: {an1 b an2 b an3 b... : n1 n2 n3... converges to ∞}

¬RX “X is a block of a’s”

Logic

Wednesday, November 18, 2009

Page 32: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

max-automata min-automata

WMSO + U WMSO + R

Wednesday, November 18, 2009

Page 33: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. WMSO+U has the same expressive power as deterministic max-automata.

max-automata min-automata

WMSO + U WMSO + R

Wednesday, November 18, 2009

Page 34: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. WMSO+U has the same expressive power as deterministic max-automata.

max-automata min-automata

eorem. WMSO+R has the same expressive power as deterministic min-automata.

WMSO + U WMSO + R

Wednesday, November 18, 2009

Page 35: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

WMSO + U + R

eorem. WMSO+U has the same expressive power as deterministic max-automata.

max-automata min-automata

eorem. WMSO+R has the same expressive power as deterministic min-automata.

What if we allow both U and R?

Wednesday, November 18, 2009

Page 36: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

WMSO + U + R

eorem. WMSO+U has the same expressive power as deterministic max-automata.

max-automata min-automata

eorem. WMSO+R has the same expressive power as deterministic min-automata.

eorem. WMSO+U+R has the same expressive power as boolean combinations of min- and max-automata.

Wednesday, November 18, 2009

Page 37: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

WMSO + U + R

eorem. WMSO+U has the same expressive power as deterministic max-automata.

eorem. WMSO+R has the same expressive power as deterministic min-automata.

eorem. WMSO+U+R has the same expressive power as boolean combinations of min- and max-automata.

Boolean combinations of min- & max-automata

Wednesday, November 18, 2009

Page 38: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

WMSO + U + R

eorem. WMSO+U has the same expressive power as deterministic max-automata.

eorem. WMSO+R has the same expressive power as deterministic min-automata.

eorem. WMSO+U+R has the same expressive power as boolean combinations of min- and max-automata.

Boolean combinations of min- & max-automata

Equivalently: Nesting the quanti$ers U and R does not contribute anything to the expressive power of WMSO.

Wednesday, November 18, 2009

Page 39: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Emptiness of min-automata

Wednesday, November 18, 2009

Page 40: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Emptiness of min-automata is decidable.

Emptiness of min-automata

Wednesday, November 18, 2009

Page 41: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Emptiness of min-automata is decidable.

1st proof. min-automata are a special case of ωBS-automata (Bojańczyk, Colcombet [06]), so emptiness is decidable. is gives bad complexity, however.

Emptiness of min-automata

Wednesday, November 18, 2009

Page 42: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Emptiness of min-automata is decidable.

1st proof. min-automata are a special case of ωBS-automata (Bojańczyk, Colcombet [06]), so emptiness is decidable. is gives bad complexity, however.

Emptiness of min-automata

2nd proof. Reduction to the limitedness problem for distance-automata. Gives PSPACE algorithm, which is optimal.

Wednesday, November 18, 2009

Page 43: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Emptiness of min-automata is decidable.

1st proof. min-automata are a special case of ωBS-automata (Bojańczyk, Colcombet [06]), so emptiness is decidable. is gives bad complexity, however.

Emptiness of min-automata

2nd proof. Reduction to the limitedness problem for distance-automata. Gives PSPACE algorithm, which is optimal.

eorem. Emptiness of max-automata is decidable.

Wednesday, November 18, 2009

Page 44: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Emptiness of min-automata is decidable.

1st proof. min-automata are a special case of ωBS-automata (Bojańczyk, Colcombet [06]), so emptiness is decidable. is gives bad complexity, however.

Emptiness of min-automata

2nd proof. Reduction to the limitedness problem for distance-automata. Gives PSPACE algorithm, which is optimal.

eorem. Emptiness of max-automata is decidable.

eorem. Emptiness of a boolean combination of min- and max-automata is decidable.

Wednesday, November 18, 2009

Page 45: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model

Wednesday, November 18, 2009

Page 46: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

Wednesday, November 18, 2009

Page 47: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

• Can introduce the unde$ned counter values ⊤ this can be eliminated by storing in the states the info about which counters are de$ned

Wednesday, November 18, 2009

Page 48: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

• Can introduce the unde$ned counter values ⊤ this can be eliminated by storing in the states the info about which counters are de$ned

• Can introduce the counter value ∞ the difference between ⊤ and ∞ is that lim ∞ = ∞ while lim ⊤≠ ∞

Wednesday, November 18, 2009

Page 49: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

• Can introduce the unde$ned counter values ⊤ this can be eliminated by storing in the states the info about which counters are de$ned

• Can introduce the counter value ∞ the difference between ⊤ and ∞ is that lim ∞ = ∞ while lim ⊤≠ ∞

• Can introduce matrix operations on counters, which stems from the semiring structure on {0,1,2,..., ∞, ⊤}, where min with respect to 0<1<2<...< ∞<⊤ is addition and + is multiplication

Wednesday, November 18, 2009

Page 50: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

• Can introduce the unde$ned counter values ⊤ this can be eliminated by storing in the states the info about which counters are de$ned

• Can introduce the counter value ∞ the difference between ⊤ and ∞ is that lim ∞ = ∞ while lim ⊤≠ ∞

• Can introduce matrix operations on counters, which stems from the semiring structure on {0,1,2,..., ∞, ⊤}, where min with respect to 0<1<2<...< ∞<⊤ is addition and + is multiplication

In Example 1, c:=c+1 can be written as:

Wednesday, November 18, 2009

Page 51: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

• Can introduce the unde$ned counter values ⊤ this can be eliminated by storing in the states the info about which counters are de$ned

• Can introduce the counter value ∞ the difference between ⊤ and ∞ is that lim ∞ = ∞ while lim ⊤≠ ∞

• Can introduce matrix operations on counters, which stems from the semiring structure on {0,1,2,..., ∞, ⊤}, where min with respect to 0<1<2<...< ∞<⊤ is addition and + is multiplication

In Example 1, c:=c+1 can be written as:

!c d z

":=

!c d z

#

$1 ! !! 0 !! ! 0

%

&

Wednesday, November 18, 2009

Page 52: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

• Can introduce the unde$ned counter values ⊤ this can be eliminated by storing in the states the info about which counters are de$ned

• Can introduce the counter value ∞ the difference between ⊤ and ∞ is that lim ∞ = ∞ while lim ⊤≠ ∞

• Can introduce matrix operations on counters, which stems from the semiring structure on {0,1,2,..., ∞, ⊤}, where min with respect to 0<1<2<...< ∞<⊤ is addition and + is multiplication

In Example 1, c:=c+1 can be written as:

!c d z

":=

!c d z

#

$1 ! !! 0 !! ! 0

%

& =!

c + 1 d z )

Wednesday, November 18, 2009

Page 53: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

• Can introduce the unde$ned counter values ⊤ this can be eliminated by storing in the states the info about which counters are de$ned

• Can introduce the counter value ∞ the difference between ⊤ and ∞ is that lim ∞ = ∞ while lim ⊤≠ ∞

• Can introduce matrix operations on counters, which stems from the semiring structure on {0,1,2,..., ∞, ⊤}, where min with respect to 0<1<2<...< ∞<⊤ is addition and + is multiplication

In Example 1, c:=c+1 can be written as:

d:=min(c,c); c:=min(z,z) can be written as:

!c d z

":=

!c d z

#

$1 ! !! 0 !! ! 0

%

& =!

c + 1 d z )

Wednesday, November 18, 2009

Page 54: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

• Can introduce the unde$ned counter values ⊤ this can be eliminated by storing in the states the info about which counters are de$ned

• Can introduce the counter value ∞ the difference between ⊤ and ∞ is that lim ∞ = ∞ while lim ⊤≠ ∞

• Can introduce matrix operations on counters, which stems from the semiring structure on {0,1,2,..., ∞, ⊤}, where min with respect to 0<1<2<...< ∞<⊤ is addition and + is multiplication

In Example 1, c:=c+1 can be written as:

d:=min(c,c); c:=min(z,z) can be written as:

!c d z

":=

!c d z

#

$1 ! !! 0 !! ! 0

%

&

!c d z

":=

!c d z

#

$! 0 !! ! !0 ! 0

%

&

=!

c + 1 d z )

Wednesday, November 18, 2009

Page 55: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

Simplyfying the min-automata model• Instructions c:=0, c:=d can be implemented into the model, as in the example

• Can introduce the unde$ned counter values ⊤ this can be eliminated by storing in the states the info about which counters are de$ned

• Can introduce the counter value ∞ the difference between ⊤ and ∞ is that lim ∞ = ∞ while lim ⊤≠ ∞

• Can introduce matrix operations on counters, which stems from the semiring structure on {0,1,2,..., ∞, ⊤}, where min with respect to 0<1<2<...< ∞<⊤ is addition and + is multiplication

In Example 1, c:=c+1 can be written as:

d:=min(c,c); c:=min(z,z) can be written as:

!c d z

":=

!c d z

#

$1 ! !! 0 !! ! 0

%

&

!c d z

":=

!c d z

#

$! 0 !! ! !0 ! 0

%

&

=!

c + 1 d z )

=!

z c z )

Wednesday, November 18, 2009

Page 56: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.

Wednesday, November 18, 2009

Page 57: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Wednesday, November 18, 2009

Page 58: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.

Wednesday, November 18, 2009

Page 59: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c.

Wednesday, November 18, 2009

Page 60: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

Wednesday, November 18, 2009

Page 61: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1

Wednesday, November 18, 2009

Page 62: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

Wednesday, November 18, 2009

Page 63: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

Wednesday, November 18, 2009

Page 64: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Wednesday, November 18, 2009

Page 65: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.

Wednesday, November 18, 2009

Page 66: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

Wednesday, November 18, 2009

Page 67: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

Wednesday, November 18, 2009

Page 68: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

Wednesday, November 18, 2009

Page 69: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...c0

c1

Wednesday, November 18, 2009

Page 70: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

c0

c1

Wednesday, November 18, 2009

Page 71: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

⊤1

c0

c1

Wednesday, November 18, 2009

Page 72: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

⊤1

1⊤

c0

c1

Wednesday, November 18, 2009

Page 73: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

⊤1

1⊤

⊤2

c0

c1

Wednesday, November 18, 2009

Page 74: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

⊤1

1⊤

⊤2

2⊤

c0

c1

Wednesday, November 18, 2009

Page 75: Deciding Emptiness of min-automata - mimuw.edu.plszymtor/talks/referat distance workshop.pdf · Deciding Emptiness of min-automata Szymon Toruńczyk joint work with Mikołaj Bojańczyk

eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

⊤1

1⊤

⊤2

2⊤

⊤2

c0

c1

Wednesday, November 18, 2009

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eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

⊤1

1⊤

⊤2

2⊤

⊤2

2⊤

c0

c1

Wednesday, November 18, 2009

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eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

⊤1

1⊤

⊤2

2⊤

⊤2

2⊤

⊤3

c0

c1

Wednesday, November 18, 2009

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eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

⊤1

1⊤

⊤2

2⊤

⊤2

2⊤

⊤3

c0

c1

3⊤

Wednesday, November 18, 2009

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eorem. Min-automata are equivalent to min-automata in matrix form, with one state.Proof. We eliminate states as in the following example.

Example. Min-automaton which counts a’s on odd positions.States: q0, q1, one counter c. Transitions:

-saw a in state q0 – go to q1; c:=c+1-saw a in state q1 – go to q0

-saw b in state q0 – go to q1

-saw b in state q1 – go to q0

Min-automaton in matrix form with one state and two counters: c0, c1.e initial counter valuation is (c0, c1)=(0, ⊤).

a :!

c0 c1

":=

!c0 c1

"·#! 01 !

$.

b :!

c0 c1

":=

!c0 c1

"·#! 00 !

$.

a a a b b b a a b...0⊤

⊤1

1⊤

⊤2

2⊤

⊤2

2⊤

⊤3

c0

c1

3⊤

⊤3

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Wednesday, November 18, 2009

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Example of a min-automaton A.

Wednesday, November 18, 2009

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Example of a min-automaton A.

0 ⊤ ⊤

⊤ 1 ⊤

⊤ ⊤ 0

1 1 ⊤

⊤ ⊤ 0

⊤ ⊤ 0a: b:

Wednesday, November 18, 2009

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Example of a min-automaton A.

0 ⊤ ⊤

⊤ 1 ⊤

⊤ ⊤ 0

1 1 ⊤

⊤ ⊤ 0

⊤ ⊤ 0a: b:

2 2 1

⊤ ⊤ 0

⊤ ⊤ 0abb:

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Example of a min-automaton A.

0 ⊤ ⊤

⊤ 1 ⊤

⊤ ⊤ 0

1 1 ⊤

⊤ ⊤ 0

⊤ ⊤ 0a: b:

2 2 1

⊤ ⊤ 0

⊤ ⊤ 0abb:

0 ⊤ ⊤Initial valuation:

Acceptance condition: ¬ liminf(c3) = ∞

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e tropical semiring

Wednesday, November 18, 2009

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e tropical semiring

T = {0,1,2,..., ∞, ⊤}

Wednesday, November 18, 2009

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e tropical semiring

T = {0,1,2,..., ∞, ⊤}ordered by 0<1<2<...<∞<⊤

with operations +, min

where ⊤+ x = x +⊤=⊤

Wednesday, November 18, 2009

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e tropical semiring

T = {0,1,2,..., ∞, ⊤}ordered by 0<1<2<...<∞<⊤

with operations +, min

Tn = {0,1,2,...,n, ∞, ⊤} where n+1=∞

where ⊤+ x = x +⊤=⊤

Wednesday, November 18, 2009

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e tropical semiring

T = {0,1,2,..., ∞, ⊤}ordered by 0<1<2<...<∞<⊤

with operations +, min

Tn = {0,1,2,...,n, ∞, ⊤} where n+1=∞

πn : T → Tn

maps n+1, n+2, ... to ∞

is a homomorphism of semirings

where ⊤+ x = x +⊤=⊤

Wednesday, November 18, 2009

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e tropical semiring

T = {0,1,2,..., ∞, ⊤}ordered by 0<1<2<...<∞<⊤

with operations +, min

Tn = {0,1,2,...,n, ∞, ⊤} where n+1=∞

πn : T → Tn

maps n+1, n+2, ... to ∞

is a homomorphism of semirings

where ⊤+ x = x +⊤=⊤

πn : Tm → Tn for m>n

Wednesday, November 18, 2009

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e tropical semiring

T = {0,1,2,..., ∞, ⊤}ordered by 0<1<2<...<∞<⊤

with operations +, min

Tn = {0,1,2,...,n, ∞, ⊤} where n+1=∞

πn : T → Tn

maps n+1, n+2, ... to ∞

is a homomorphism of semirings

where ⊤+ x = x +⊤=⊤

πn : Tm → Tn for m>n

Wednesday, November 18, 2009

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e tropical semiring

T = {0,1,2,..., ∞, ⊤}ordered by 0<1<2<...<∞<⊤

with operations +, min

Tn = {0,1,2,...,n, ∞, ⊤} where n+1=∞

πn : T → Tn

maps n+1, n+2, ... to ∞

is a homomorphism of semirings

where ⊤+ x = x +⊤=⊤

πn : Tm → Tn for m>n

MkT – k by k matrices over Twith matrix multiplication

MkTn – k by k matrices over Tnwith matrix multiplication

πn : MkT → MkTn

maps n+1, n+2, ... to ∞

is a homomorphism of semirings

πn : Tm → Tn for m>n

Wednesday, November 18, 2009

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e tropical semiring

T = {0,1,2,..., ∞, ⊤}ordered by 0<1<2<...<∞<⊤

with operations +, min

Tn = {0,1,2,...,n, ∞, ⊤} where n+1=∞

πn : T → Tn

maps n+1, n+2, ... to ∞

is a homomorphism of semirings

where ⊤+ x = x +⊤=⊤

πn : Tm → Tn for m>n

MkT – k by k matrices over Twith matrix multiplication

MkTn – k by k matrices over Tnwith matrix multiplication

πn : MkT → MkTn

maps n+1, n+2, ... to ∞

is a homomorphism of semirings

πn : Tm → Tn for m>n

3 ∞ 10 ∞ 12 ∞ ∞

3 32 10 11 12 7 ∞

∞ ∞ 10 ∞ 1∞ ∞ ∞

π6 π2

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Pro$nite monoid

Wednesday, November 18, 2009

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Pro$nite monoid

S0 S1 S2 S3 S7 S32 S1000

Wednesday, November 18, 2009

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Pro$nite monoid

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

Wednesday, November 18, 2009

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Pro$nite monoid

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

M3T0 M3T1 M3T2 M3T3

Wednesday, November 18, 2009

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Pro$nite monoid

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

Wednesday, November 18, 2009

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Pro$nite monoid

3 ∞ 10 ∞ 12 ∞ ∞

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.

Wednesday, November 18, 2009

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Pro$nite monoid

∞ ∞ 10 ∞ 12 ∞ ∞

3 ∞ 10 ∞ 12 ∞ ∞

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

..

Wednesday, November 18, 2009

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Pro$nite monoid

∞ ∞ 10 ∞ 1∞ ∞ ∞

∞ ∞ 10 ∞ 12 ∞ ∞

3 ∞ 10 ∞ 12 ∞ ∞

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

...

Wednesday, November 18, 2009

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Pro$nite monoid

∞ ∞ ∞0 ∞ ∞∞ ∞ ∞

∞ ∞ 10 ∞ 1∞ ∞ ∞

∞ ∞ 10 ∞ 12 ∞ ∞

3 ∞ 10 ∞ 12 ∞ ∞

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

....

Wednesday, November 18, 2009

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Pro$nite monoid

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

....

Wednesday, November 18, 2009

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Pro$nite monoid

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

-approximation:0

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.... . . .........................

∞ ∞ ∞0 ∞ ∞∞ ∞ ∞

Wednesday, November 18, 2009

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Pro$nite monoid

-approximation:1

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.... . . .........................

∞ ∞ 10 ∞ 1∞ ∞ ∞

Wednesday, November 18, 2009

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Pro$nite monoid

-approximation:2

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.... . . .........................

∞ ∞ 10 ∞ 12 ∞ ∞

Wednesday, November 18, 2009

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Pro$nite monoid

-approximation:3

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.... . . .........................

3 ∞ 10 ∞ 12 ∞ ∞

Wednesday, November 18, 2009

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Pro$nite monoid

-approximation:3 ∞ 10 ∞ 12 7 ∞

7

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

-approximation:3 32 10 11 12 7 ∞

1000

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish them

S0 S1 S2 S3 S7 S32 S1000

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish them

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish them

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish them

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish them

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish them

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish them

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish them

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish them

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

e n-approximation of x·y is the product of their n-approximations.we again obtain a sequence consistent with the mappings

multiplication

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

e n-approximation of x·y is the product of their n-approximations.we again obtain a sequence consistent with the mappings

3 8 43 8 45 18 3

=

multiplication

·

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

e n-approximation of x·y is the product of their n-approximations.we again obtain a sequence consistent with the mappings

3 8 43 8 45 18 3

=

is continuous

multiplication

·

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

e n-approximation of x·y is the product of their n-approximations.we again obtain a sequence consistent with the mappings

3 8 43 8 45 18 3

=

is continuous

...................

multiplication

·

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

e n-approximation of x·y is the product of their n-approximations.we again obtain a sequence consistent with the mappings

3 8 43 8 45 18 3

=

is continuous

.....................................

multiplication

·

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

3 8 43 8 45 18 3

=

is continuous

.....................................

multiplication

·

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

3 8 43 8 45 18 3

=

is continuous

.....................................

multiplicationaddition

·

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

3 8 43 8 45 18 3

=

is continuous

.....................................

multiplicationaddition

addition

·

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

3 8 43 8 45 18 3

=

is continuous

.....................................

multiplicationaddition

addition

idempotent power (ω)

·

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

3 8 43 8 45 18 3

=

is continuous

.....................................

multiplicationaddition

addition

idempotent power (ω)

ω-power

·

.... . . .........................

Wednesday, November 18, 2009

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Pro$nite monoid

3 32 10 11 12 7 ∞

Metric Two elements are close if only an approx. with high threshold can distinguish themMultiplication

S0 S1 S2 S3 S7 S32 S1000

. . . . . . .........................

3 50 10 11 12 7 ∞

}d = 2-32

preserve

. . . . . . .........................

3 8 43 8 45 18 3

=

is continuous

.....................................

multiplicationaddition

addition

idempotent power (ω)

ω-power

·

compact space.... . . .........................

Wednesday, November 18, 2009

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Wednesday, November 18, 2009

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Example of a min-automaton A.

Wednesday, November 18, 2009

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Example of a min-automaton A.

0 ⊤ ⊤

⊤ 1 ⊤

⊤ ⊤ 0

1 1 ⊤

⊤ ⊤ 0

⊤ ⊤ 0a: b:

∞ ∞ 1⊤ ⊤ 0

⊤ ⊤ 0bω:

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

.x x x x x x x x x x x x x x x x x x x x x x x x x

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

.x x x x x x x x x x x x x x x x x x x x x x x x x

colored by elements of a compact space

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

.x x x x x x x x x x x x x x x x x x x x x x x x x . . .. . . . . .

..colored by elements of a compact space

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

.x x x x x x x x x x x x x x x x x x x x x x x x x . . .. . . . . .

..

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

.x x x x x x x x x x x x x x x x x x x x x x x x x . . .. . . . . .

...

. .

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

.x x x x x x x x x x x x x x x x x x x x x x x x x . . .. . . . . .

...

. .

.

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . ..

. .

.x x x x x x x x x x x x x x x

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . ..

. .

.x x x x x x x x x x x x x x x

. .

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . ..

. .

.x x x x x x x x x x x x x x x

. .

.

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . ..

. .

.x x x x x x x x x x x x x x x

. .

.x x

.

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . ..

. .

.x x x x x x x x x x x x x x x

. .

.x x

..

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . ..

. .

.x x x x x x x x x x x x x x x

. .

.x x

.. .

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . ..

. .

.x x x x x x x x x x x x x x x

. .

.x x

.. .

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . .. .

.x x x x x x x x x x x x x x x

.

.x x .x

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . .. .

.x x x x x x x x x x x x x x x

.

.x x .x

lim

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . .. .

.x x x x x x x x x x x x x x x

.

.x x .

x x x x x x x x x x x x x x x x x x x x x x x x x

x

lim

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . .. .

.x x x x x x x x x x x x x x x

.

.x x .

x x x x x x x x x x x x x x x x x x x x x x x x x .

x

lim

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . .. .

.x x x x x x x x x x x x x x x

.

.x x .

x x x x x x x x x x x x x x x x x x x x x x x x x .

x

lim

d( , )<1/Nlim

N

Wednesday, November 18, 2009

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Ramsey eoremfor compact spaces

x x x x x x x x x x x x x x x x x x x x x x x x x . .. .

.x x x x x x x x x x x x x x x

.

.x x .

x x x x x x x x x x x x x x x x x x x x x x x x x ..

x

lim

d( , )<1/Nlim d( , )<1/N’lim

N N'

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x

x x x x x x x x x x x x x x x x x x x x x x x x x

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x

x x x x x x x x x x x x x x x x x x x x x x x x x

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . . . . . ..

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . . . . . ..induced transition matrix

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . . .. . . . . .

..

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lim

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lim

Counter c does not converge to ∞ iff exists a counter d such that lim[d,d]=0 and lim[d,c]< ∞.

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lim

Which limits lim are possible?

Counter c does not converge to ∞ iff exists a counter d such that lim[d,d]=0 and lim[d,c]< ∞.

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lim

Which limits lim are possible?

Counter c does not converge to ∞ iff exists a counter d such that lim[d,d]=0 and lim[d,c]< ∞.

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b

Which limits lim are possible?

Counter c does not converge to ∞ iff exists a counter d such that lim[d,d]=0 and lim[d,c]< ∞.

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b

Which limits lim are possible?

Counter c does not converge to ∞ iff exists a counter d such that lim[d,d]=0 and lim[d,c]< ∞.

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b ( , )+Which limits lim are possible?

Counter c does not converge to ∞ iff exists a counter d such that lim[d,d]=0 and lim[d,c]< ∞.

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b ( , )+__________

∈Which limits lim are possible?

Counter c does not converge to ∞ iff exists a counter d such that lim[d,d]=0 and lim[d,c]< ∞.

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b ( , )+__________

∈Which limits lim are possible?

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b ( , )+__________

eorem.

Which limits lim are possible?

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b ( , )+__________

eorem. a b ( , )+__________

Which limits lim are possible?

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b ( , )+__________

eorem. =a b ( , )+__________

Which limits lim are possible?

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b ( , )+__________

eorem. a b=a b ( , )+__________

Which limits lim are possible?

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b ( , )+__________

eorem. a b ( , )+,ω=a b ( , )+__________

Which limits lim are possible?

Wednesday, November 18, 2009

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Emptiness of min-automata

a b b a a b a a b a b b a a a b b a b a b a x x x .x x x x x x x x x x x x x x x x x x x x x x x x x . ..

lim

d( , )<1/19)lim

. ..

.d( , )<1/10lim

d( , )<1/15lima b ( , )+__________

eorem. a b ( , )+,ω=if , are matrices over the (min,+)-semiring.a b

a b ( , )+__________

Which limits lim are possible?

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # )

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

• s # = (s n )# for n=1,2,3,...

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

• s # = (s n )# for n=1,2,3,...• (s t)# s = s (t s)#

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

• s # = (s n )# for n=1,2,3,...• (s t)# s = s (t s)#

• s# s# = s#

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

• s # = (s n )# for n=1,2,3,...• (s t)# s = s (t s)#

• s# s# = s#

• e# e = e# if e is idempotent

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

• s # = (s n )# for n=1,2,3,...• (s t)# s = s (t s)#

• s# s# = s#

• e# e = e# if e is idempotent

e = e# if e is idempotent

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

• s # = (s n )# for n=1,2,3,...• (s t)# s = s (t s)#

• s# s# = s#

• e# e = e# if e is idempotent

e = e# if e is idempotent

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

• s # = (s n )# for n=1,2,3,...• (s t)# s = s (t s)#

• s# s# = s#

• e# e = e# if e is idempotent

e = e# if e is idempotent

Example 1 (in$nite) ({0,1,2,..., ∞}, +, ω ), 0ω =0, 1ω = 2ω = ...= ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

• s # = (s n )# for n=1,2,3,...• (s t)# s = s (t s)#

• s# s# = s#

• e# e = e# if e is idempotent

e = e# if e is idempotent

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Example 1 (in$nite) ({0,1,2,..., ∞}, +, ω ), 0ω =0, 1ω = 2ω = ...= ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

semigroup with stabilization

( S , · , # ){

• s # = (s n )# for n=1,2,3,...• (s t)# s = s (t s)#

• s# s# = s#

• e# e = e# if e is idempotent

e = e# if e is idempotent

1,2,3... → 1Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Example 1 (in$nite) ({0,1,2,..., ∞}, +, ω ), 0ω =0, 1ω = 2ω = ...= ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

1 1 1 10 0 0 1

1 1 1 1

1 1

1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

1 1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

1 1 1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

01 1 1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

01 1 1 1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

01 1 1 1

1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

0 01 1 1 1

1 1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

10 0 0 0 0 00001 1 1 1 10

0 01 1 1 1

1 1

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Simon’s Factorization eoremfor semigroups with stabilization

Factorization tree of word w ∈ S+

Use the two rules to construct tree:binary rule idempotent rule

s t

st

e ee e

e#

eorem. For any $nite stabilization semigroup S and word w ∈ S+ there exists a factorization tree over w of height ≤ 9|S|2.

Example 2 ($nite) ({0,1, ∞}, +, # ), 1+1=1, 0# =0, 1# = ∞# = ∞

Wednesday, November 18, 2009

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Wednesday, November 18, 2009

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ank you for your attention!

Wednesday, November 18, 2009