attribute to disable occur check

[gares]

TODO:

• :nooc on pred
• check if rule has _ and if/how it interacts
• add a unsound_unif builtin/std
• see if the determinacy checker can also track/infer groundness too hard
• test if calling ground_term to ensure dynamically things are ok is sustainable. on the bench file, almost no overhead.

[gares]

Idea: attach nooc only to predicates, then statically error if an output arg contains _ or if a goal does.
This way the optimization should stay sound wrt _.

It could still create cyclic terms. For that one could do an analysis based on det check to track groundness of generated output, where ground_term is the original seed. Since nooc is opt-in, this is not mandatory.

[gares]

??