Added basic normalization tests.

These tests make sure that simple PDDL descriptions are preserved by
normalization.

tests/data/normalization/normalization-1.pddl

@@ -0,0 +1,45 @@
+; tests that a simple PDDL description is preserved by normalization
+(define (domain test-normalization)
+	(:requirements :typing)
+	(:types block gripper)
+
+	(:predicates
+		(test-predicate-0)
+		(test-predicate-1 ?x - block)
+		(test-predicate-2 ?x - block ?y - gripper))
+
+	(:action test-action-1
+		:parameters
+			(?x - block)
+		:precondition
+			(test-predicate-1 ?x)
+		:effect
+			(test-predicate-1 ?x))
+
+	(:action test-action-2
+		:parameters
+			(?x - block ?y - gripper)
+		:precondition
+			(and
+				(not (test-predicate-0))
+				(test-predicate-2 ?x ?y))
+		:effect
+			(test-predicate-2 ?x ?y))
+)
+
+(define (problem test-normalization)
+	(:domain test-normalization)
+
+	(:objects a b c d - block e f - gripper)
+
+	(:init
+		(test-predicate-0)
+		(test-predicate-1 a)
+		(test-predicate-1 d)
+		(test-predicate-2 a e)
+		(test-predicate-2 c f))
+
+	(:goal (and
+		(test-predicate-0)
+		(not (test-predicate-1 d))
+		(test-predicate-2 b f))))