NPPL - Network Picture Processing Language. Interactive language for manipulation of digraphs. Dov Gabbay, J Logic Programming. Interactive creation of formal mathematics, including definitions and proofs. An extremely rich type system, including dependent functions, products, sets, quotients and universes.
Types are first-class citizens.
A Prolog with 'when' declarations, the successor to MU-Prolog. NYAP - Early system on IBM 704.