[fspeech]

Prolog is neat. There is probably a Prolog embedded in some of the C++ type checkers. The problem is that the world at large is often in a flux and can't be conveniently described in terms of static relationships, which makes Prolog programming at large challenging to do (or you augment Prolog with features that make it more or less imperative).

[JadeNB]

> The problem is that the world at large is often in a flux and can't be conveniently described in terms of static relationships

Apparently there was work in the late '90's on accounting for this without `assert` / `retract`-style messiness: https://en.wikipedia.org/wiki/Transaction_logic.