Added normalization tests for nested expressions.

These tests ensure that nested expressions in preconditions and effects
are correctly flattened via derived predicates.

tests/data/normalization/normalization-5.pddl

@@ -0,0 +1,58 @@
+(define (domain test-normalization)
+	(:predicates
+		(p1 ?x ?y)
+		(p2 ?x ?y)
+		(p3 ?x ?y)
+		(p4 ?x ?y)
+		(p5 ?x ?y ?z)
+		(p6 ?x ?y ?z)
+		(p7 ?x ?y)
+		(p8 ?x)
+		(p9 ?x))
+
+	(:action test-action-1
+		:parameters
+			(?x
+			?y)
+		:precondition
+			(and
+				(forall
+					(?z)
+					(imply
+						(p1 ?y ?z)
+						(p2 ?z ?y)))
+				(p3 ?x ?y)
+				(or
+					(and
+						(p4 ?x ?y)
+						(forall
+							(?z)
+							(imply
+								(p5 ?z ?x ?y)
+								(p3 ?z ?y))))
+					(and
+						(p7 ?x ?y)
+						(not (exists
+							(?z ?a)
+							(and
+								(p6 ?z ?a ?y)
+								(p3 ?z ?y)))))))
+		:effect
+			(and
+				(not (p3 ?x ?y))
+				(p9 ?x)
+				(when
+					(and
+						(not (forall
+							(?p)
+							(and
+								(not (p7 ?p ?y))
+								(not (p3 ?y ?p)))))
+						(exists
+							(?z ?a)
+							(or
+								(p4 ?z ?a)
+								(p3 ?a ?z))))
+					(and
+						(p8 ?y)
+						(p9 ?y))))))