Write a predicate
min_conflicts(Vars,Count)
that takes two arguments:
The specification of min_conflicts(Vars,Count)
is as follows:
cs
is empty, instantiate Vars
to
their tentative values
V
, in a conflict constraint
V
to the value (0 or 1) that maximises
the tentative value of Count
V
the other way.
This can be tested with the following propositional satisfiability program.
cons_clause(Clause,Bool) :- Clause =:= 1 r_conflict cs, Bool tent_is Clause. prop_sat(Vars,List) :- ( foreach(N,List), foreach(Cl,Clauses), param(Vars) do cl(N,Vars,Cl) ), init_tent_values(Vars), ( foreach(Cl,Clauses), foreach(B,Bools) do cons_clause(Cl,B) ), Count tent_is sum(Bools), min_conflicts(Vars,Count). init_tent_values(Vars) :- ( foreach(V,Vars) do V tent_set 1). cl(1,[X,Y,Z], (X or neg Y or Z)). cl(2,[X,Y,Z], (neg X or neg Y)). cl(3,[X,Y,Z], (Y or neg Z)). cl(4,[X,Y,Z], (X or neg Z)). cl(5,[X,Y,Z], (Y or Z)). |
To test your program try the following queries:
?- prop_sat([X,Y,Z],[1,2,3]). ?- prop_sat([X,Y,Z],[1,2,3,4]). ?- prop_sat([X,Y,Z],[1,2,3,4,5]).