LARA

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
Last revision Both sides next revision
sav08:finite-model_finders [2008/03/13 12:02]
vkuncak
sav08:finite-model_finders [2008/03/13 13:24]
vkuncak
Line 9: Line 9:
 For a given bound $k$, is there an interpretation of a given formula with a domain of size $k$? For a given bound $k$, is there an interpretation of a given formula with a domain of size $k$?
  
-This problem is decidable.+This problem is decidable: consider domain $\{1,​\ldots,​n\}$. ​ The number of all possible interpretations with this domain is finite.
  
 Finite model finder: a tool that searches for such models. Finite model finder: a tool that searches for such models.
  
 Approaches: Approaches:
-  * encoding into SAT (popular recently because SAT solvers are good): MACE, Paradox, KodKod (used in Alloy) 
   * generalize SAT algorithms to search for finite domains and not just propositional ones (SEM)   * generalize SAT algorithms to search for finite domains and not just propositional ones (SEM)
 +  * encoding into SAT (popular recently because SAT solvers are good): MACE, Paradox, KodKod (used in Alloy)
 +
 +Issues when encoding into SAT:
 +  * detecting sharing to minimizing size of propositional formula
 +  * symmetry breaking - larger formula with fewer instances
 +  * sort inference - smaller range of variables
 +  * incremental search for different sizes of the domain - reusing work in SAT solver
 +
 +Symmetry breaking among issues of encoding into SAT.
  
 ===== References ===== ===== References =====
  
-  * [[http://​alloy.mit.edu]] 
   * [[http://​web.mit.edu/​~emina/​www/​kodkod.html]]   * [[http://​web.mit.edu/​~emina/​www/​kodkod.html]]
   * [[http://​www.cs.chalmers.se/​~koen/​folkung/​]]   * [[http://​www.cs.chalmers.se/​~koen/​folkung/​]]
 +  * [[http://​alloy.mit.edu]]