# {X + Y \>= 1} fails - bug?

**URL:** <https://swi-prolog.discourse.group/t/x-y-1-fails-bug/5193>\
**Category:** Help!\
**Tags:** clpr\
**Created:** [March 30, 2022, 7:05pm UTC](https://swi-prolog.discourse.group/t/x-y-1-fails-bug/5193 "2022-03-30T19:05:17Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![brebs](https://avatars.discourse-cdn.com/v4/letter/b/e9c0ed/32.png) [@brebs](https://swi-prolog.discourse.group/u/brebs)\
**Post date:** [March 30, 2022, 7:05pm UTC](https://swi-prolog.discourse.group/t/x-y-1-fails-bug/5193/1 "2022-03-30T19:05:17Z")

</div>

Given (as per [example in docs](https://www.swi-prolog.org/man/clpqr.html)):

```prolog
?- use_module(library(clpr)).
?- {X + Y >= 1}.

```

In swi-prolog 8.5.8 and 8.5.9 it fails:

```prolog
false.

```

But in 8.4.2 and 8.5.7 it succeeds:

```prolog
{Y=1.0-X+_A, _A>=0.0}.

```

The [8.5.8 announcement](https://swi-prolog.discourse.group/t/ann-swi-prolog-8-5-8/5102) did mention potential regressions. Am seeking reassurance that this is an actual bug, before reporting it 🙂

---

<div class="post-metadata">

**Author:** ![jan](https://yyz2.discourse-cdn.com/free1/user_avatar/swi-prolog.discourse.group/jan/32/4_2.png) [@jan](https://swi-prolog.discourse.group/u/jan)\
**Post date:** [March 31, 2022, 7:06am UTC](https://swi-prolog.discourse.group/t/x-y-1-fails-bug/5193/2 "2022-03-31T07:06:58Z")

</div>

Thanks! Pushed a fix.