On second thought, these are mostly too closely related, I think that if you want to truly find the ur-specification languages this is closely related to Girard's research program. Specification languages are intrinsically tied to a notion of truth and also of proof (method of establishing / showing truth), these are central questions in Girard's work.

I think a revised list should also include proof-nets, and other weirder specification languages like the [flower calculus](http://www.lix.polytechnique.fr/Labo/Pablo.DONATO/drafts/FJ....) or stellar resolution. These also stretch the usual interpretation of language as a syntax tree.