LOP - Language based on first-order logic. "SETHEO - A High-Perormance
Theorem Prover for First-Order Logic", Reinhold Letz et al, J Automated
Reasoning 8(2):183-212 (1992).
LOP Programming Language
http://www.programming-languages.co.uk/lop.html
Large list of computer programming languages arranged alphabetically, with explanations.