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disable tracking literals, they are not used

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added trivial rewrites for set.size
This commit is contained in:
Nikolaj Bjorner 2025-10-26 16:21:33 +01:00
parent a66cb88c78
commit c832802183
3 changed files with 42 additions and 16 deletions
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44
src/ast/rewriter/finite_set_rewriter.cpp
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@ -16,6 +16,7 @@ Author:
--*/
#include "ast/rewriter/finite_set_rewriter.h"
#include "ast/arith_decl_plugin.h"
br_status finite_set_rewriter::mk_app_core(func_decl * f, unsigned num_args, expr * const * args, expr_ref & result) {
SASSERT(f->get_family_id() == get_fid());
@ -37,6 +38,9 @@ br_status finite_set_rewriter::mk_app_core(func_decl * f, unsigned num_args, exp
case OP_FINITE_SET_IN:
SASSERT(num_args == 2);
return mk_in(args[0], args[1], result);
case OP_FINITE_SET_SIZE:
// Size is already in normal form, no simplifications
return mk_size(args[0], result);
default:
return BR_FAILED;
}
@ -147,26 +151,26 @@ br_status finite_set_rewriter::mk_difference(expr * arg1, expr * arg2, expr_ref
br_status finite_set_rewriter::mk_subset(expr * arg1, expr * arg2, expr_ref & result) {
// set.subset(x, x) -> true
if (arg1 == arg2) {
result = m().mk_true();
result = m.mk_true();
return BR_DONE;
}
// set.subset(empty, x) -> true
if (m_util.is_empty(arg1)) {
result = m().mk_true();
result = m.mk_true();
return BR_DONE;
}
// set.subset(x, empty) -> x = empty
if (m_util.is_empty(arg2)) {
result = m().mk_eq(arg1, arg2);
result = m.mk_eq(arg1, arg2);
return BR_REWRITE1;
}
// General case: set.subset(x, y) -> set.intersect(x, y) = x
expr_ref intersect(m());
expr_ref intersect(m);
intersect = m_util.mk_intersect(arg1, arg2);
result = m().mk_eq(intersect, arg1);
result = m.mk_eq(intersect, arg1);
return BR_REWRITE3;
}
@ -175,10 +179,34 @@ br_status finite_set_rewriter::mk_singleton(expr * arg, expr_ref & result) {
return BR_FAILED;
}
br_status finite_set_rewriter::mk_size(expr * arg, expr_ref & result) {
arith_util a(m);
if (m_util.is_empty(arg)) {
// size(empty) -> 0
result = a.mk_int(0);
return BR_DONE;
}
if (m_util.is_singleton(arg)) {
// size(singleton(x)) -> 1
result = a.mk_int(1);
return BR_DONE;
}
expr *lower, *upper;
if (m_util.is_range(arg, lower, upper)) {
// size(range(a, b)) -> b - a + 1
expr_ref size_expr(m);
size_expr = a.mk_add(a.mk_sub(upper, lower), a.mk_int(1));
result = m.mk_ite(a.mk_gt(lower, upper), a.mk_int(0), size_expr);
return BR_REWRITE3;
}
// Size is already in normal form, no simplifications
return BR_FAILED;
}
br_status finite_set_rewriter::mk_in(expr * elem, expr * set, expr_ref & result) {
// set.in(x, empty) -> false
if (m_util.is_empty(set)) {
result = m().mk_false();
result = m.mk_false();
return BR_DONE;
}
@ -187,11 +215,11 @@ br_status finite_set_rewriter::mk_in(expr * elem, expr * set, expr_ref & result)
if (m_util.is_singleton(set, singleton_elem)) {
// set.in(x, singleton(x)) -> true (when x is the same)
if (elem == singleton_elem) {
result = m().mk_true();
result = m.mk_true();
return BR_DONE;
}
// set.in(x, singleton(y)) -> x = y (when x != y)
result = m().mk_eq(elem, singleton_elem);
result = m.mk_eq(elem, singleton_elem);
return BR_REWRITE1;
}