added short readme on how to use existing prolog code to run the exam…

…ples.

prolog/README.txt

@@ -0,0 +1,26 @@
+Code developed and tested with SWI-prolog 5.7.11 & 5.10.4
+
+To try example1.pl:
+* fire up prolog in interactive mode (pl, or swipl command usually) in the 
+  same directory as exampleZ.pl and dpj.pl
+
+* load example1.pl (remember the colon):
+	?- ['example1.pl'].
+  exampleZ.pl will also load its dependency, dpj.pl
+
+* query the predicate:
+	(a) to find solutions
+		?- example1(X,Y).
+
+	(b) to check if a specific solution is valid
+		?- example1(root, star).
+
+	(c) to check if given a partial solution, a full solution can be found
+		?- example1(root, Y).
+
+For examples 2 & 3 the procedure is similar, although I recommend you quit 
+and start over the prolog interpreter to purge all the loaded predicates 
+that may interfere from one example to the other. (I'm going to figure out  
+a way to scope this predicates to prevent them from leaking from one example
+to the other).
+