z3-z3-4.13.0.src.ast.array_peq.h Maven / Gradle / Ivy
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/*++
Copyright (c) 2023 Microsoft Corporation
Module Name:
array_peq.h
Abstract:
Partial equality for arrays
Author:
Nikolaj Bjorner (nbjorner) 2015-06-13
Hari Govind V K
Revision History:
--*/
#pragma once
#include "ast/array_decl_plugin.h"
#include "ast/ast.h"
/**
* \brief utility class for partial equalities
*
* A partial equality (a ==I b), for two arrays a, b and a finite set of indices
* I holds iff (forall i :: i \not\in I => a[i] == b[i]). In other words, peq is
* a restricted form of the extensionality axiom
*
* Using this class, we denote (a =I b) as f(a,b,i0,i1,...),
* where f is an uninterpreted predicate with the name PARTIAL_EQ and
* I = {i0,i1,...}
*/
class peq {
ast_manager &m;
expr_ref m_lhs;
expr_ref m_rhs;
vector m_diff_indices;
func_decl_ref m_decl; // the partial equality declaration
app_ref m_peq; // partial equality application
app_ref m_eq; // equivalent std equality using def. of partial eq
array_util m_arr_u;
symbol m_name;
public:
peq(app *p, ast_manager &m);
peq(expr *lhs, expr *rhs, vector const &diff_indices,
ast_manager &m);
expr_ref lhs() { return m_lhs; }
expr_ref rhs() { return m_rhs; }
void get_diff_indices(vector &result) {
result.append(m_diff_indices);
}
/** Convert peq into a peq expression */
app_ref mk_peq();
/** Convert peq into an equality
For peq of the form (a =I b) returns (a = b[i0 := v0, i1 := v1, ...])
where i0, i1 \in I, and v0, v1 are fresh skolem constants
Skolems are returned in aux_consts
The left and right hand arguments are reversed when stores_on_rhs is
false
*/
app_ref mk_eq(app_ref_vector &aux_consts, bool stores_on_rhs = true);
};
/**
* mk (e0 ==indices e1)
*
* result has stores if either e0 or e1 or an index term has stores
*/
app_ref mk_peq(expr *e0, expr *e1, vector const &indices,
ast_manager &m);
bool is_partial_eq(const func_decl *f);
bool is_partial_eq(const app *a);
inline bool is_peq(const func_decl *f) { return is_partial_eq(f); }
inline bool is_peq(const app *a) { return is_partial_eq(a); }