Modify logic for "not" operator.

Assets/Cryville/Crtr/PdtEvaluator.cs

@@ -231,7 +231,7 @@ namespace Cryville.Crtr {
 		class op_not_1 : PdtOperator {
 			public op_not_1() : base(1) { }
 			protected override void Execute() {
-				float result = GetOperand(0).AsNumber() == 0 ? 1 : 0;
+				float result = GetOperand(0).AsNumber() <= 0 ? 1 : 0;
 				GetReturnFrame(PdtInternalType.Number, sizeof(float)).SetNumber(result);
 			}
 		}