Implement "disjunction"

[turion]

There is conjunction, which is helpful, but there is no corresponding function generalizing or.

[alfert]

That is an interesting idea. conjunction is implemented in proper as specific part of all properties, including data generation etc (starting here: https://github.com/proper-testing/proper/blob/bfd7d862dd5082eeca65c192a7021d0e4de5973e/src/proper.erl#L1151).

I assume (gut feeling only) that a disjunction makes dealing with counterexamples and shrinking way more difficult and for this reason it is not implemented. I would suggest to discuss with the people from Proper. If they add it to their execution engine, I am happy to include it here as well.