mirrors/z3
3
0
Fork 0
mirror of https://github.com/Z3Prover/z3 synced 2025-05-06 15:25:46 +00:00
Code Activity

add notes and tangent lemma

Browse source 
Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
This commit is contained in:
Nikolaj Bjorner 2021-09-21 11:30:50 -07:00
parent 0426b23d0c
commit 444084f396
6 changed files with 49 additions and 13 deletions
Download patch file Download diff file Expand all files Collapse all files

25
src/math/polysat/saturation.cpp
View file

@ -42,6 +42,8 @@ namespace polysat {
return true;
if (try_y_l_ax_and_x_l_z(v, core, c))
return true;
if (try_tangent(v, core, c))
return true;
}
return false;
}
@ -380,4 +382,27 @@ namespace polysat {
return propagate(core, z_l_y, yx_l_zx, z_l_y.is_strict || yx_l_zx.is_strict, y * x, y_prime * x, new_constraints);
}
// [x] p(x) <= q(x) where value(p) > value(q)
// ==> q <= value(q) => p <= value(q)
bool inf_saturate::try_tangent(pvar v, conflict& core, inequality const& c) {
if (!c.src->contains_var(v))
return false;
if (c.lhs.is_val() || c.rhs.is_val())
return false;
if (!c.as_signed_constraint().is_currently_false(s()))
return false;
rational l_val, r_val;
if (!s().try_eval(c.lhs, l_val))
return false;
if (!s().try_eval(c.rhs, r_val))
return false;
SASSERT(c.is_strict || l_val > r_val);
SASSERT(!c.is_strict || l_val >= r_val);
vector<signed_constraint> new_constraints;
new_constraints.push_back(c.as_signed_constraint());
new_constraints.push_back(s().ule(c.rhs, r_val));
return propagate(core, c, c, c.is_strict ? s().ult(c.lhs, r_val) : s().ule(c.lhs, r_val), new_constraints);
}
}