Z3 sources

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2025-08-03 18:00:23 +00:00 · 2012-10-02 11:35:25 -07:00 · 2012-10-02 11:35:25 -07:00 · e9eab22e5c
commit e9eab22e5c
parent 3f9edad676
1186 changed files with 381859 additions and 0 deletions
--- a/lib/arith_solver_plugin.cpp
+++ b/lib/arith_solver_plugin.cpp
@ -0,0 +1,104 @@
+/*++
+Copyright (c) 2006 Microsoft Corporation
+
+Module Name:
+
+    arith_solver_plugin.cpp
+
+Abstract:
+
+    <abstract>
+
+Author:
+
+    Leonardo de Moura (leonardo) 2008-06-30.
+
+Revision History:
+
+--*/
+#include"arith_solver_plugin.h"
+#include"ast_pp.h"
+
+arith_solver_plugin::arith_solver_plugin(arith_simplifier_plugin & simp):
+    solver_plugin(symbol("arith"), simp.get_manager()),
+    m_simplifier(simp) {
+}
+
+bool arith_solver_plugin::solve(expr * lhs, expr * rhs, expr_mark const & forbidden, app_ref & var, expr_ref & subst) {
+    rational k;
+    if (!m_simplifier.is_numeral(rhs, k))
+        return false;
+    bool _is_int = m_simplifier.is_int(lhs);
+    ptr_buffer<expr> monomials;
+    ptr_buffer<expr> todo;
+    bool already_found = false;
+    rational c;
+    todo.push_back(lhs);
+    while (!todo.empty()) {
+        expr * curr = todo.back();
+        todo.pop_back();
+        rational coeff;
+        if (m_simplifier.is_add(curr)) {
+            SASSERT(to_app(curr)->get_num_args() == 2);
+            todo.push_back(to_app(curr)->get_arg(1));
+            todo.push_back(to_app(curr)->get_arg(0));
+        }
+        else {
+            if (!already_found) {
+                if (m_simplifier.is_mul(curr) && 
+                    m_simplifier.is_numeral(to_app(curr)->get_arg(0), coeff) && !coeff.is_zero() && (!_is_int || coeff.is_minus_one()) && 
+                    is_uninterp_const(to_app(curr)->get_arg(1)) &&
+                    !forbidden.is_marked(to_app(curr)->get_arg(1))) {
+                    c             = coeff;
+                    var           = to_app(to_app(curr)->get_arg(1));
+                    already_found = true;
+                }
+                else if (is_uninterp_const(curr) && !forbidden.is_marked(curr)) {
+                    c             = rational::one();
+                    var           = to_app(curr);
+                    already_found = true;
+                }
+                else {
+                    monomials.push_back(curr);
+                }
+            }
+            else {
+                monomials.push_back(curr);
+            }
+        }
+    }
+    if (!already_found)
+        return false;
+    SASSERT(!c.is_zero());
+    k /= c;
+    expr_ref_vector new_monomials(m_manager);
+    if (!k.is_zero())
+        new_monomials.push_back(m_simplifier.mk_numeral(k, _is_int));
+    c.neg();
+    expr_ref inv_c(m_manager);
+    if (!c.is_one()) {
+        rational inv(1);
+        inv /= c;
+        inv_c = m_simplifier.mk_numeral(inv, _is_int);
+    }
+    // divide monomials by c
+    unsigned sz = monomials.size();
+    for (unsigned i = 0; i < sz; i++) {
+        expr * m       = monomials[i];
+        expr_ref new_m(m_manager); 
+        if (!c.is_one())
+            m_simplifier.mk_mul(inv_c, m, new_m);
+        else
+            new_m = m;
+        new_monomials.push_back(new_m);
+    }
+    if (new_monomials.empty()) 
+        subst = m_simplifier.mk_numeral(rational(0), _is_int);
+    else
+        m_simplifier.mk_add(new_monomials.size(), new_monomials.c_ptr(), subst);
+    TRACE("arith_solver", tout << "solving:\n" << mk_pp(lhs, m_manager) << "\n" << mk_pp(rhs, m_manager) 
+          << "\nresult:\n" << mk_pp(var, m_manager) << "\n" << mk_pp(subst, m_manager) << "\n";);
+    return true;
+}
+
+