45 lines
1 KiB
C++
45 lines
1 KiB
C++
|
/*
|
||
|
|
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
|
||
|
|
Released under Apache 2.0 license as described in the file LICENSE.
|
||
|
|
|
||
|
|
Author: Leonardo de Moura
|
||
|
|
*/
|
||
|
|
#include "library/expr_pair.h"
|
||
|
|
#include "kernel/kernel.h"
|
||
|
|
|
||
|
|
namespace lean {
|
||
|
|
bool is_equality(expr const & e) {
|
||
|
|
return is_eq(e) || is_iff(e) || is_heq(e);
|
||
|
|
}
|
||
|
|
|
||
|
|
bool is_equality(expr const & e, expr & lhs, expr & rhs) {
|
||
|
|
if (is_eq(e)) {
|
||
|
|
lhs = arg(e, 2);
|
||
|
|
rhs = arg(e, 3);
|
||
|
|
return true;
|
||
|
|
} else if (is_iff(e)) {
|
||
|
|
lhs = arg(e, 1);
|
||
|
|
rhs = arg(e, 2);
|
||
|
|
return true;
|
||
|
|
} else if (is_heq(e)) {
|
||
|
|
lhs = heq_lhs(e);
|
||
|
|
rhs = heq_rhs(e);
|
||
|
|
return true;
|
||
|
|
} else {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
expr_pair get_equality_args(expr const & e) {
|
||
|
|
if (is_eq(e)) {
|
||
|
|
return mk_pair(arg(e, 2), arg(e, 3));
|
||
|
|
} else if (is_iff(e)) {
|
||
|
|
return mk_pair(arg(e, 1), arg(e, 2));
|
||
|
|
} else if (is_heq(e)) {
|
||
|
|
return mk_pair(heq_lhs(e), heq_rhs(e));
|
||
|
|
} else {
|
||
|
|
lean_unreachable(); // LCOV_EXCL_LINE
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|