See the "Typing" section of https://sforman.srht.site/PLSemProlog.html https://sforman.srht.site/PLSemProlog.html Note that there's no implementation of the typ

See the "Typing" section of https://sforman.srht.site/PLSemProlog.html https://sforman.srht.site/PLSemProlog.html Note that there's no implementation of the type inference algorithm, just descriptions of the type relations. That's because Prolog itself is the type inference algorithm.