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proof format

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Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2022-06-06 07:18:33 -07:00
parent ea365de820
commit b629960afb
8 changed files with 144 additions and 62 deletions
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44
src/sat/smt/arith_proof_checker.h
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@ -40,6 +40,8 @@ namespace arith {
row m_ineq;
row m_conseq;
vector<row> m_eqs;
vector<row> m_ineqs;
vector<row> m_diseqs;
void add(row& r, expr* v, rational const& coeff) {
rational coeff1;
@ -241,6 +243,26 @@ namespace arith {
return false;
}
//
// checking disequalities is TBD.
// it has to select only a subset of bounds to justify each inequality.
// example
// c <= x <= c, c <= y <= c => x = y
// for the proof of x <= y use the inequalities x <= c <= y
// for the proof of y <= x use the inequalities y <= c <= x
// example
// x <= y, y <= z, z <= u, u <= x => x = z
// for the proof of x <= z use the inequalities x <= y, y <= z
// for the proof of z <= x use the inequalities z <= u, u <= x
//
// so when m_diseqs is non-empty we can't just add inequalities with Farkas coefficients
// into m_ineq, since coefficients of the usable subset vanish.
//
bool check_diseq() {
return false;
}
std::ostream& display_row(std::ostream& out, row const& r) {
bool first = true;
for (auto const& [v, coeff] : r.m_coeffs) {
@ -270,6 +292,11 @@ namespace arith {
out << " <= 0\n";
}
row& fresh(vector<row>& rows) {
rows.push_back(row());
return rows.back();
}
public:
proof_checker(ast_manager& m): m(m), a(m) {}
@ -278,10 +305,14 @@ namespace arith {
m_ineq.reset();
m_conseq.reset();
m_eqs.reset();
m_ineqs.reset();
m_diseqs.reset();
m_strict = false;
}
bool add_ineq(rational const& coeff, expr* e, bool sign) {
if (!m_diseqs.empty())
return add_literal(fresh(m_ineqs), abs(coeff), e, sign);
return add_literal(m_ineq, abs(coeff), e, sign);
}
@ -290,14 +321,21 @@ namespace arith {
}
void add_eq(expr* a, expr* b) {
m_eqs.push_back(row());
row& r = m_eqs.back();
row& r = fresh(m_eqs);
linearize(r, rational(1), a);
linearize(r, rational(-1), b);
}
void add_diseq(expr* a, expr* b) {
row& r = fresh(m_diseqs);
linearize(r, rational(1), a);
linearize(r, rational(-1), b);
}
bool check() {
if (!m_conseq.m_coeffs.empty())
if (!m_diseqs.empty())
return check_diseq();
else if (!m_conseq.m_coeffs.empty())
return check_bound();
else
return check_farkas();