[EtDybNuvCu]

Interesting syntax. Can Picat programs be run backwards or in other-than-expected directions, as in Prologs and Kanrens? This relational aspect is the killer feature of logical languages, and it would be unfortunate if Picat doesn't have it.

[doublec]

Yes, it's possible in picat. For example, here's factorial in picat that can be computed backwards: http://www.hakank.org/picat/factorial_reversible.pi