Qu-prolog 4.3 reference manual
Peter Robinson, Richard A. Hagen · 1999
Qu-Prolog is an extension of Prolog designed primarily as an implementation and tactic language for interactive theorem provers, particularly those that carry out schematic proofs. Qu-Prolog has built-in support for the kinds of data structures typically encountered in theorem proving activities such as object variables, substitutions and quantified terms. Qu-Prolog also supports interprocess communication (IPC) that allows messages to be passed between Qu-Prolog threads, whether they are executing on the same Qu-Prolog process or on different processes or even on different machines.