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working on new interpolation

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This commit is contained in:
Ken McMillan 2013-10-25 13:58:56 -07:00
parent 3a0947b3ba
commit 79b0f83ab3
3 changed files with 691 additions and 35 deletions
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70
src/interp/iz3translate.cpp
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@ -829,6 +829,42 @@ public:
return make_int(d);
}
ast get_bounded_variable(const ast &ineq, bool &lb){
ast nineq = normalize_inequality(ineq);
ast lhs = arg(nineq,0);
switch(op(lhs)){
case Uninterpreted:
lb = false;
return lhs;
case Times:
if(arg(lhs,0) == make_int(rational(1)))
lb = false;
else if(arg(lhs,0) == make_int(rational(-1)))
lb = true;
else
throw unsupported();
return arg(lhs,1);
default:
throw unsupported();
}
}
rational get_term_coefficient(const ast &t1, const ast &v){
ast t = arg(normalize_inequality(t1),0);
if(op(t) == Plus){
int nargs = num_args(t);
for(int i = 0; i < nargs; i++){
if(get_linear_var(arg(t,i)) == v)
return get_coeff(arg(t,i));
}
}
else
if(get_linear_var(t) == v)
return get_coeff(t);
return rational(0);
}
Iproof::node GCDtoDivRule(const ast &proof, bool pol, std::vector<rational> &coeffs, std::vector<Iproof::node> &prems, ast &cut_con){
// gather the summands of the desired polarity
std::vector<Iproof::node> my_prems;
@ -843,6 +879,24 @@ public:
}
}
ast my_con = sum_inequalities(my_coeffs,my_prem_cons);
// handle generalized GCD test. sadly, we dont' get the coefficients...
if(coeffs[0].is_zero()){
bool lb;
int xtra_prem = 0;
ast bv = get_bounded_variable(conc(prem(proof,0)),lb);
rational bv_coeff = get_term_coefficient(my_con,bv);
if(bv_coeff.is_pos() != lb)
xtra_prem = 1;
if(bv_coeff.is_neg())
bv_coeff = -bv_coeff;
my_prems.push_back(prems[xtra_prem]);
my_coeffs.push_back(make_int(bv_coeff));
my_prem_cons.push_back(conc(prem(proof,xtra_prem)));
my_con = sum_inequalities(my_coeffs,my_prem_cons);
}
my_con = normalize_inequality(my_con);
Iproof::node hyp = iproof->make_hypothesis(mk_not(my_con));
my_prems.push_back(hyp);
@ -961,6 +1015,12 @@ public:
else
lits.push_back(from_ast(con));
// special case
if(dk == PR_MODUS_PONENS && pr(prem(proof,0)) == PR_QUANT_INST && pr(prem(proof,1)) == PR_REWRITE ) {
res = iproof->make_axiom(lits);
return res;
}
// translate all the premises
std::vector<Iproof::node> args(nprems);
for(unsigned i = 0; i < nprems; i++)
@ -1057,6 +1117,10 @@ public:
res = iproof->make_hypothesis(conc(proof));
break;
}
case PR_QUANT_INST: {
res = iproof->make_axiom(lits);
break;
}
default:
assert(0 && "translate_main: unsupported proof rule");
throw unsupported();
@ -1066,6 +1130,11 @@ public:
return res;
}
void clear_translation(){
translation.first.clear();
translation.second.clear();
}
// We actually compute the interpolant here and then produce a proof consisting of just a lemma
iz3proof::node translate(ast proof, iz3proof &dst){
@ -1075,6 +1144,7 @@ public:
ast itp = translate_main(proof);
itps.push_back(itp);
delete iproof;
clear_translation();
}
// Very simple proof -- lemma of the empty clause with computed interpolation
iz3proof::node Ipf = dst.make_lemma(std::vector<ast>(),itps); // builds result in dst