INSTALLATION GUIDE Yadlr is written in Prolog using attributed variables and the clp(Q,R) extension. You can compile and run using either Yap 5.1 or later of SWI-Prolog 5.6 or later. It might be possible to compile using other Prolog implementations or versions, but they are neither tested nor supported. You can get Yap from http://yap.sourceforge.net/ and SWI-Prolog from http://www.swi-prolog.org/ You need to compile with attributed variables and co-routining (see configure options for Yap or SWI-Prolog about how to do this) and also include the clp(Q,R) package in your Prolog installation.