Part of them is the tool Proof Tree. In it you can see how your goal was satisfied. You can see its Proof Tree and even open its sub-branches by double clicking. We hope that you will like this possibility, especially, because you have not got it in any other Prolog compiler. These are variables which are visible in the whole program, not in one clause only.
Global variables are very convenient as illustrated in the examples.
In version 1.2 the way in which you can define functions is changed. If you want to get familiar with the environment and the syntax of Strawberry Prolog then we recommend you Strawberry Prolog Tutorial which is part of the documentation of our product. You can find it in our Help file. If you want to download programs written on Strawberry Prolog then go to Software . We offer you Photographs and additional information about the presentation of Strawberry Prolog version 1.0 which was made in the University of Sofia on 3 December 1998.