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On Reducing Maximum Independent Set to Minimum Satis fiabili ty Ale x - - PowerPoint PPT Presentation

A. Ignatiev, A. Morgado, and J. Marques-Silva On Reducing MIS to MinSAT / On Reducing Maximum Independent Set to Minimum Satis fiabili ty Ale x e y Ig n a t ie v , A nton i o Mor gad o , a n d J o a o M a rqu e s - S il v a ,


slide-1
SLIDE 1
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

On Reducing Maximum Independent Set to Minimum Satisfiability

Alexey Ignatiev, Antonio Morgado, and Joao Marques-Silva,

 INESC-ID/IST, Lisbon, Portugal  CASL/CSI, University College Dublin, Ireland

th International Conference on Theory and Applications of Satisfiability Testing Vienna, Austria July , 

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SLIDE 2
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Problems statements

MIS: compute the largest number of pairwise non-connected vertices in G. MVC: compute the smallest number of vertices in G that are incident to all edges of G.

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SLIDE 3
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Problems statements

MIS: compute the largest number of pairwise non-connected vertices in G. MVC: compute the smallest number of vertices in G that are incident to all edges of G. ⇓ Given G, I ⊆ G is an MIS solution ⇔ G \ I is an MVC solution.

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SLIDE 4
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Problems statements

MIS: compute the largest number of pairwise non-connected vertices in G. MVC: compute the smallest number of vertices in G that are incident to all edges of G. ⇓ Given G, I ⊆ G is an MIS solution ⇔ G \ I is an MVC solution. MaxClq = MIS

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SLIDE 5
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Problems statements

MIS: compute the largest number of pairwise non-connected vertices in G. MVC: compute the smallest number of vertices in G that are incident to all edges of G. ⇓ Given G, I ⊆ G is an MIS solution ⇔ G \ I is an MVC solution. MaxClq = MIS MinSAT: compute the smallest number of simultaneously satisfied clauses in F. MaxFalse: compute the largest number of simultaneously falsified clauses in F.

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SLIDE 6
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Problems statements

MIS: compute the largest number of pairwise non-connected vertices in G. MVC: compute the smallest number of vertices in G that are incident to all edges of G. ⇓ Given G, I ⊆ G is an MIS solution ⇔ G \ I is an MVC solution. MaxClq = MIS MinSAT: compute the smallest number of simultaneously satisfied clauses in F. MaxFalse: compute the largest number of simultaneously falsified clauses in F. ⇓ Given F, M ⊆ F is a MaxFalse solution ⇔ F \ M is a MinSAT solution.

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SLIDE 7
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

MIS and MaxFalse

MIS ↔ MaxFalse MVC ↔ MinSAT

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SLIDE 8
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Basic reduction

v v v v v

F =            c = x, c = ¬x, ∨ x, ∨ x, ∨ x, c = ¬x, ∨ x, c = ¬x, c = ¬x, ∨ ¬x,           

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SLIDE 9
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Basic reduction

v v v v v

F =            c = x, c = ¬x, ∨ x, ∨ x, ∨ x, c = ¬x, ∨ x, c = ¬x, c = ¬x, ∨ ¬x,           

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SLIDE 10
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Basic reduction

v v v v v

F =            c = x, c = ¬x, ∨ x, ∨ x, ∨ x, c = ¬x, ∨ x, c = ¬x, c = ¬x, ∨ ¬x,           

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SLIDE 11
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Basic reduction

v v v v v

F =            c = x, c = ¬x, ∨ x, ∨ x, ∨ x, c = ¬x, ∨ x, c = ¬x, c = ¬x, ∨ ¬x,           

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SLIDE 12
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Basic reduction

v v v v v

F =            c = x, c = ¬x, ∨ x, ∨ x, ∨ x, c = ¬x, ∨ x, c = ¬x, c = ¬x, ∨ ¬x,           

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SLIDE 13
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Basic reduction

v v v v v

F =            c = x, c = ¬x, ∨ x, ∨ x, ∨ x, c = ¬x, ∨ x, c = ¬x, c = ¬x, ∨ ¬x,           

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SLIDE 14
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Basic reduction

v v v v v

F =            c = x, c = ¬x, ∨ x, ∨ x, ∨ x, c = ¬x, ∨ x, c = ¬x, c = ¬x, ∨ ¬x,            Given a graph G = (V, E), basic reduction constructs a formula F with exactly |V| clauses and |E| variables.

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SLIDE 15
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Greedy reduction

v v v v v

F =            c = ¬x c = x c = ¬x ∨ x c = ¬x c = ¬x ∨ ¬x           

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SLIDE 16
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Greedy reduction

v v v v v

F =            c = ¬x c = x c = ¬x ∨ x c = ¬x c = ¬x ∨ ¬x           

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SLIDE 17
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Greedy reduction

v v v v v

F =            c = ¬x c = x c = ¬x ∨ x c = ¬x c = ¬x ∨ ¬x           

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SLIDE 18
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Greedy reduction

v v v v v

F =            c = ¬x c = x c = ¬x ∨ x c = ¬x c = ¬x ∨ ¬x            Given a graph G = (V, E), greedy reduction constructs a formula F with exactly |V| clauses and |V| variables.

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SLIDE 19
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Variable compatibility

  • riginal idea — compatible states in finite-state machines simplification
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SLIDE 20
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Variable compatibility

  • riginal idea — compatible states in finite-state machines simplification

compatible variables can replace each other

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SLIDE 21
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Variable compatibility

  • riginal idea — compatible states in finite-state machines simplification

compatible variables can replace each other variable compatibility rules:

no tautology given a clause ¬x ∨ x, variables x and x are not compatible

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SLIDE 22
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Variable compatibility

  • riginal idea — compatible states in finite-state machines simplification

compatible variables can replace each other variable compatibility rules:

no tautology given a clause ¬x ∨ x, variables x and x are not compatible

no new connection given two clauses ¬x ∨ x and ¬x, variables x and x are not compatible

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SLIDE 23
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Variable compatibility

v v v v v

(a) Graph G

c = x c = ¬x ∨ x ∨ x ∨ x c = ¬x ∨ x c = ¬x c = ¬x ∨ ¬x

(b) Set of clauses for G

x x x x x x – x **, – x **, – x **, – x *, * *, –

Literal compatibility is similar.

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SLIDE 24
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Variable compatibility

v v v v v

(a) Graph G

c = x c = ¬x ∨ x ∨ x ∨ x c = ¬x ∨ x c = ¬x c = ¬x ∨ ¬x

(b) Set of clauses for G

x x x x x x – x **, – x **, – x **, – x *, * *, –

Literal compatibility is similar.

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SLIDE 25
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Variable compatibility

v v v v v

(a) Graph G

c = x c = ¬x ∨ x ∨ x ∨ x c = ¬x ∨ x c = ¬x c = ¬x ∨ ¬x

(b) Set of clauses for G

x x x x x x – x **, – x **, – x **, – x *, * *, –

Literal compatibility is similar.

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SLIDE 26
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Weighting clauses and removing duplicates

basic greedy greedy+vc vars clauses time vars clauses time vars clauses time Instance c-fat-

  .   .   

c-fat-

  .   .   

c-fat-

  .   .   

c-fat-

  —   .   

c-fat-

  —   .   

c-fat-

  —   .   

c-fat-

  —   .   

Running time for MinSatz.

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SLIDE 27
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

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SLIDE 28
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc.

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SLIDE 29
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc. MIS instances obtained from Binate Covering Problem benchmarks (BCP)

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SLIDE 30
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc. MIS instances obtained from Binate Covering Problem benchmarks (BCP)

 Tools:

MaxCLQ — native MaxClq solver

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SLIDE 31
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc. MIS instances obtained from Binate Covering Problem benchmarks (BCP)

 Tools:

MaxCLQ — native MaxClq solver MinSatz — branch and bound MinSAT solver

slide-32
SLIDE 32
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc. MIS instances obtained from Binate Covering Problem benchmarks (BCP)

 Tools:

MaxCLQ — native MaxClq solver MinSatz — branch and bound MinSAT solver MaxSatz — branch and bound MaxSAT solver

slide-33
SLIDE 33
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc. MIS instances obtained from Binate Covering Problem benchmarks (BCP)

 Tools:

MaxCLQ — native MaxClq solver MinSatz — branch and bound MinSAT solver MaxSatz — branch and bound MaxSAT solver MiFuMaX — Fu&Malik algorithm for MaxSAT (best for MS industrial in )

slide-34
SLIDE 34
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc. MIS instances obtained from Binate Covering Problem benchmarks (BCP)

 Tools:

MaxCLQ — native MaxClq solver MinSatz — branch and bound MinSAT solver MaxSatz — branch and bound MaxSAT solver MiFuMaX — Fu&Malik algorithm for MaxSAT (best for MS industrial in )

Machine configuration:

Intel Xeon @GHz with GB RAM

slide-35
SLIDE 35
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc. MIS instances obtained from Binate Covering Problem benchmarks (BCP)

 Tools:

MaxCLQ — native MaxClq solver MinSatz — branch and bound MinSAT solver MaxSatz — branch and bound MaxSAT solver MiFuMaX — Fu&Malik algorithm for MaxSAT (best for MS industrial in )

Machine configuration:

Intel Xeon @GHz with GB RAM running Fedora Linux

slide-36
SLIDE 36
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc. MIS instances obtained from Binate Covering Problem benchmarks (BCP)

 Tools:

MaxCLQ — native MaxClq solver MinSatz — branch and bound MinSAT solver MaxSatz — branch and bound MaxSAT solver MiFuMaX — Fu&Malik algorithm for MaxSAT (best for MS industrial in )

Machine configuration:

Intel Xeon @GHz with GB RAM running Fedora Linux GB memout

slide-37
SLIDE 37
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental evaluation

Benchmarks ( in total):

crafted MaxClq instances: DIMACS MaxClq, FRB, etc. MIS instances obtained from Binate Covering Problem benchmarks (BCP)

 Tools:

MaxCLQ — native MaxClq solver MinSatz — branch and bound MinSAT solver MaxSatz — branch and bound MaxSAT solver MiFuMaX — Fu&Malik algorithm for MaxSAT (best for MS industrial in )

Machine configuration:

Intel Xeon @GHz with GB RAM running Fedora Linux GB memout

 Timeout value —  seconds

slide-38
SLIDE 38
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental results

— CLQ MinSz MaxSz-d MaxSz-mf FM-d FM-mf VBS-d VBS-mf VBS Native MaxFalse-based Direct MaxSAT

slide-39
SLIDE 39
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Experimental results

— CLQ MinSz MaxSz-d MaxSz-mf FM-d FM-mf VBS-d VBS-mf VBS Native MaxFalse-based Direct MaxSAT

CLQ MinSz MaxSz-d MaxSz-mf FM-d FM-mf VBS-d VBS-mf VBS Crafted Clq

        

BCP

        

Total

        

slide-40
SLIDE 40
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Performance of the considered approaches

20 40 60 80 100 120 140 160 instances 1 10 100 1000 CPU time (s) VBS MaxFalse VBS MaxCLQ MinSatz Direct MaxSAT VBS MaxSatz-dir MaxSatz-mf MiFuMaX-mf MiFuMaX-dir

slide-41
SLIDE 41
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Summary and future work

proposed a reduction from MIS to MinSAT

slide-42
SLIDE 42
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Summary and future work

proposed a reduction from MIS to MinSAT

 heuristics to reduce obtained MinSAT formulas

slide-43
SLIDE 43
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Summary and future work

proposed a reduction from MIS to MinSAT

 heuristics to reduce obtained MinSAT formulas 

experimental results:

comparable to native MaxClq solvers

slide-44
SLIDE 44
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Summary and future work

proposed a reduction from MIS to MinSAT

 heuristics to reduce obtained MinSAT formulas 

experimental results:

comparable to native MaxClq solvers

  • utperforms MaxSAT-based approaches
slide-45
SLIDE 45
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Summary and future work

proposed a reduction from MIS to MinSAT

 heuristics to reduce obtained MinSAT formulas 

experimental results:

comparable to native MaxClq solvers

  • utperforms MaxSAT-based approaches

portfolios of solvers

slide-46
SLIDE 46
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Summary and future work

proposed a reduction from MIS to MinSAT

 heuristics to reduce obtained MinSAT formulas 

experimental results:

comparable to native MaxClq solvers

  • utperforms MaxSAT-based approaches

portfolios of solvers

further improvements to the proposed MinSAT models

slide-47
SLIDE 47
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Summary and future work

proposed a reduction from MIS to MinSAT

 heuristics to reduce obtained MinSAT formulas 

experimental results:

comparable to native MaxClq solvers

  • utperforms MaxSAT-based approaches

portfolios of solvers

further improvements to the proposed MinSAT models

 portfolios of solvers for NP-hard graph problems

slide-48
SLIDE 48
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Summary and future work

proposed a reduction from MIS to MinSAT

 heuristics to reduce obtained MinSAT formulas 

experimental results:

comparable to native MaxClq solvers

  • utperforms MaxSAT-based approaches

portfolios of solvers

further improvements to the proposed MinSAT models

 portfolios of solvers for NP-hard graph problems 

development of efficient MinSAT solvers

slide-49
SLIDE 49
  • A. Ignatiev, A. Morgado, and J. Marques-Silva

On Reducing MIS to MinSAT /

Tank you for your attention!