Documentation for + and - symbols in the documentation

[jgarte]

Hi,

Where is the documentation for + and - symbols in the documentation introduced?

I couldn't find it 🦆

Example:

I was able to find this documentation in swi-prolog docs but should we give our own introduction so that is self-contained here without needing to refer to swi-prolog's documentation?

https://www.swi-prolog.org/pldoc/man?section=modes

[jgarte]

BTW, I discovered the above swi-prolog documentation by asking Claude about these symbols in the context of modern ISO Prolog arcana. Claude pointed me to swi-prolog's docs.

[UWN]

The precise meaning is a bit flaky including the less-than-optimal doc you cite, in particular in SWI which has its very own interpretation. More information.