small prolog 2.0 by Henri de Feraudy (found at https://github.com/rebcabin/LINQdoesLogic ) and updated to compile without warnings.
Famous from Dr Dobbs http://www.drdobbs.com/cpp/extending-c-with-prolog/184409294
Longer writeup here: http://web.archive.org/web/20040603192757/research.microsoft.com/research/dtg/davidhov/pap.htm
Currently only works on OSX (64bit) Darwin 14.5.0 Darwin Kernel Version 14.5.0: Wed Jul 29 02:26:53 PDT 2015; root:xnu-2782.40.9~1/RELEASE_X86_64 x86_64