Empty list ambiguity

[amimart]

Description

When comparing an empty list [] with the '[]' atom, it is considered equal.

How to reproduce

This issue can be easily reproduced using the provided interactive interpreter cmd/1pl:

?- [] = '[]'.
true

I'd be happy to have your thoughts about that, if I can be of any help it'll be a pleasure :)

[pmoura]

The empty list is an atom in ISO Prolog Core standard and in almost all Prolog systems (*). There's no bug here.

(*) The only exception is SWI-Prolog which made the (questionable and very publicly criticized decision) to make [] its own type in release 7.x.

[amimart]

Oh I see, thanks @pmoura :)