Note from Christoph Lehner
and thank you for being interested in my tree drawing program. If you like it and use it, please be fair and mention where you found it. Also, tell me, if you don't like it or encounter any problems during the process of installation.
Be aware that although there is supposed to be an ISO standard for Prolog there are no two different Prolog systems that are 100% identical. The handling of predefined predicates is especially delicate and causes many errors that can however be resolved very easily.
Try to check whether standard predicates like append/3 or member/2 are automatically loaded in your system. If that is the case, you may just place quote characters around the definitions or delete them in the file you downloaded to avoid error messages.
If you have any additional problems occuring during the process of installing the program or anything else that occurs while using prolog send me email.
And now have fun using Prolog and implementing Natural Language Programs.
BTW: I am planning to set up a page on simple German morphology. So, if you are interested in that or in testing Prolog programs dealing with German morphology or morphology in general, please check in from time to time. I will give notice about the ongoings here.