[derdi]

Yes, enumerating all predicates in the system and meta-interpreting all control structures seems unrealistic to me. In the sense that no Prolog application developer (as opposed to a Prolog system implementor) would want to do it. Except maybe as an intellectual exercise.

Of course you wouldn't really need to enumerate all predicates in the definition of call/1. You could first run a whole-program abstract interpretation to identify just the ones that can actually be meta-called. Much more appealing :-)

[falsissime]

Yes, this technique has been used by several implementations. And any application developer can use `asserta/1` for the very same purpose. Just one rule, that is certainly much more appealing.