ABSYS

ABSYS was an early declarative language[?] from the University of Aberdeen which anticipated a number of features of Prolog.

["ABSYS: An Incremental Compiler for Assertions", J.M. Foster et al, Mach Intell 4, Edinburgh U Press, 1969, pp. 423-429].

This article was originally based on material from FOLDOC, used with permission. Update as needed.