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fixed several interpolation problems

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Ken McMillan 2014-04-10 17:53:17 -07:00
parent f7d589fc49
commit de81db9a3b
3 changed files with 128 additions and 7 deletions
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11
src/interp/iz3base.cpp
View file

@ -260,7 +260,7 @@ void iz3base::check_interp(const std::vector<ast> &itps, std::vector<ast> &theor
#endif
}
bool iz3base::is_sat(const std::vector<ast> &q, ast &_proof){
bool iz3base::is_sat(const std::vector<ast> &q, ast &_proof, std::vector<ast> &vars){
params_ref p;
p.set_bool("proof", true); // this is currently useless
@ -277,6 +277,15 @@ bool iz3base::is_sat(const std::vector<ast> &q, ast &_proof){
::ast *proof = s.get_proof();
_proof = cook(proof);
}
else if(vars.size()) {
model_ref(_m);
s.get_model(_m);
for(unsigned i = 0; i < vars.size(); i++){
expr_ref r(m());
_m.get()->eval(to_expr(vars[i].raw()),r,true);
vars[i] = cook(r.get());
}
}
dealloc(m_solver);
return res != l_false;
}

2
src/interp/iz3base.h
View file

@ -113,7 +113,7 @@ class iz3base : public iz3mgr, public scopes {
void check_interp(const std::vector<ast> &itps, std::vector<ast> &theory);
/** For convenience -- is this formula SAT? */
bool is_sat(const std::vector<ast> &consts, ast &_proof);
bool is_sat(const std::vector<ast> &consts, ast &_proof, std::vector<ast> &vars);
/** Interpolator for clauses, to be implemented */
virtual void interpolate_clause(std::vector<ast> &lits, std::vector<ast> &itps){

122
src/interp/iz3translate.cpp
View file

@ -1071,6 +1071,8 @@ public:
ast AssignBounds2Farkas(const ast &proof, const ast &con){
std::vector<ast> farkas_coeffs;
get_assign_bounds_coeffs(proof,farkas_coeffs);
if(farkas_coeffs[0] != make_int(rational(1)))
farkas_coeffs[0] = make_int(rational(1));
std::vector<ast> lits;
int nargs = num_args(con);
if(nargs != (int)(farkas_coeffs.size()))
@ -1107,6 +1109,8 @@ public:
ast AssignBoundsRule2Farkas(const ast &proof, const ast &con, std::vector<Iproof::node> prems){
std::vector<ast> farkas_coeffs;
get_assign_bounds_rule_coeffs(proof,farkas_coeffs);
if(farkas_coeffs[0] != make_int(rational(1)))
farkas_coeffs[0] = make_int(rational(1));
std::vector<ast> lits;
int nargs = num_prems(proof)+1;
if(nargs != (int)(farkas_coeffs.size()))
@ -1278,6 +1282,17 @@ public:
return make(Plus,args);
}
void get_sum_as_vector(const ast &t, std::vector<rational> &coeffs, std::vector<ast> &vars){
if(!(op(t) == Plus)){
coeffs.push_back(get_coeff(t));
vars.push_back(get_linear_var(t));
}
else {
int nargs = num_args(t);
for(int i = 0; i < nargs; i++)
get_sum_as_vector(arg(t,i),coeffs,vars);
}
}
ast replace_summands_with_fresh_vars(const ast &t, hash_map<ast,ast> &map){
if(op(t) == Plus){
@ -1294,6 +1309,94 @@ public:
return map[t];
}
rational lcd(const std::vector<rational> &rats){
rational res = rational(1);
for(unsigned i = 0; i < rats.size(); i++){
res = lcm(res,denominator(rats[i]));
}
return res;
}
Iproof::node reconstruct_farkas_with_dual(const std::vector<ast> &prems, const std::vector<Iproof::node> &pfs, const ast &con){
int nprems = prems.size();
std::vector<ast> npcons(nprems);
hash_map<ast,ast> pain_map; // not needed
for(int i = 0; i < nprems; i++)
npcons[i] = painfully_normalize_ineq(conc(prems[i]),pain_map);
ast ncon = painfully_normalize_ineq(mk_not(con),pain_map);
npcons.push_back(ncon);
hash_map<ast,ast> dual_map;
std::vector<ast> cvec, vars_seen;
ast rhs = make_real(rational(0));
for(unsigned i = 0; i < npcons.size(); i++){
ast c= mk_fresh_constant("@c",real_type());
cvec.push_back(c);
ast lhs = arg(npcons[i],0);
std::vector<rational> coeffs;
std::vector<ast> vars;
get_sum_as_vector(lhs,coeffs,vars);
for(unsigned j = 0; j < coeffs.size(); j++){
rational coeff = coeffs[j];
ast var = vars[j];
if(dual_map.find(var) == dual_map.end()){
dual_map[var] = make_real(rational(0));
vars_seen.push_back(var);
}
ast foo = make(Plus,dual_map[var],make(Times,make_real(coeff),c));
dual_map[var] = foo;
}
rhs = make(Plus,rhs,make(Times,c,arg(npcons[i],1)));
}
std::vector<ast> cnstrs;
for(unsigned i = 0; i < vars_seen.size(); i++)
cnstrs.push_back(make(Equal,dual_map[vars_seen[i]],make_real(rational(0))));
cnstrs.push_back(make(Leq,rhs,make_real(rational(0))));
for(unsigned i = 0; i < cvec.size() - 1; i++)
cnstrs.push_back(make(Geq,cvec[i],make_real(rational(0))));
cnstrs.push_back(make(Equal,cvec.back(),make_real(rational(1))));
ast new_proof;
// greedily reduce the core
for(unsigned i = 0; i < cvec.size() - 1; i++){
std::vector<ast> dummy;
cnstrs.push_back(make(Equal,cvec[i],make_real(rational(0))));
if(!is_sat(cnstrs,new_proof,dummy))
cnstrs.pop_back();
}
std::vector<ast> vals = cvec;
if(!is_sat(cnstrs,new_proof,vals))
throw "Proof error!";
std::vector<rational> rat_farkas_coeffs;
for(unsigned i = 0; i < cvec.size(); i++){
ast bar = vals[i];
rational r;
if(is_numeral(bar,r))
rat_farkas_coeffs.push_back(r);
else
throw "Proof error!";
}
rational the_lcd = lcd(rat_farkas_coeffs);
std::vector<ast> farkas_coeffs;
std::vector<Iproof::node> my_prems;
std::vector<ast> my_pcons;
for(unsigned i = 0; i < prems.size(); i++){
ast fc = make_int(rat_farkas_coeffs[i] * the_lcd);
if(!(fc == make_int(rational(0)))){
farkas_coeffs.push_back(fc);
my_prems.push_back(pfs[i]);
my_pcons.push_back(conc(prems[i]));
}
}
farkas_coeffs.push_back(make_int(the_lcd));
my_prems.push_back(iproof->make_hypothesis(mk_not(con)));
my_pcons.push_back(mk_not(con));
Iproof::node res = iproof->make_farkas(mk_false(),my_prems,my_pcons,farkas_coeffs);
return res;
}
ast painfully_normalize_ineq(const ast &ineq, hash_map<ast,ast> &map){
ast res = normalize_inequality(ineq);
ast lhs = arg(res,0);
@ -1318,7 +1421,8 @@ public:
npcons.push_back(ncon);
// ast assumps = make(And,pcons);
ast new_proof;
if(is_sat(npcons,new_proof))
std::vector<ast> dummy;
if(is_sat(npcons,new_proof,dummy))
throw "Proof error!";
pfrule dk = pr(new_proof);
int nnp = num_prems(new_proof);
@ -1334,7 +1438,7 @@ public:
farkas_coeffs.push_back(make_int(rational(1)));
}
else
throw "cannot reconstruct farkas proof";
return reconstruct_farkas_with_dual(prems,pfs,con);
for(int i = 0; i < nnp; i++){
ast p = conc(prem(new_proof,i));
@ -1348,7 +1452,7 @@ public:
my_pcons.push_back(mk_not(con));
}
else
throw "cannot reconstruct farkas proof";
return reconstruct_farkas_with_dual(prems,pfs,con);
}
Iproof::node res = iproof->make_farkas(mk_false(),my_prems,my_pcons,farkas_coeffs);
return res;
@ -1378,7 +1482,8 @@ public:
npcons.push_back(ncon);
// ast assumps = make(And,pcons);
ast new_proof;
if(is_sat(npcons,new_proof))
std::vector<ast> dummy;
if(is_sat(npcons,new_proof,dummy))
throw "Proof error!";
pfrule dk = pr(new_proof);
int nnp = num_prems(new_proof);
@ -1408,7 +1513,7 @@ public:
my_pcons.push_back(mk_not(con));
}
else
throw "cannot reconstruct farkas proof";
return painfully_reconstruct_farkas(prems,pfs,con);
}
Iproof::node res = iproof->make_farkas(mk_false(),my_prems,my_pcons,farkas_coeffs);
return res;
@ -1552,6 +1657,13 @@ public:
if(dk == PR_MODUS_PONENS && expect_clause && op(con) == Or)
std::cout << "foo!\n";
// no idea why this shows up
if(dk == PR_MODUS_PONENS_OEQ)
if(conc(prem(proof,0)) == con){
res = translate_main(prem(proof,0),expect_clause);
return res;
}
#if 0
if(1 && dk == PR_TRANSITIVITY && pr(prem(proof,1)) == PR_COMMUTATIVITY){
Iproof::node clause = translate_main(prem(proof,0),true);