diff --git a/Assets/Cryville/Crtr/PdtEvaluator.cs b/Assets/Cryville/Crtr/PdtEvaluator.cs
index 6b54dc7..cacc0ad 100644
--- a/Assets/Cryville/Crtr/PdtEvaluator.cs
+++ b/Assets/Cryville/Crtr/PdtEvaluator.cs
@@ -95,6 +95,14 @@ namespace Cryville.Crtr {
 			else throw new KeyNotFoundException(string.Format("Undefined operator {0}({1})", name, pc));
 		}
 
+		protected override bool Collapse(string name, PdtVariableMemory param) {
+			switch (name) {
+				case "&": return param.AsNumber() == 0;
+				case "|": return param.AsNumber() != 0;
+				default: throw new KeyNotFoundException(string.Format("Undefined collapse operator {0}", name));
+			}
+		}
+
 		public ChartEvent ContextEvent { private get; set; }
 		public Transform ContextTransform { private get; set; }
 		public Judge ContextJudge { private get; set; }
@@ -120,13 +128,11 @@ namespace Cryville.Crtr {
 		}
 		static PdtEvaluator() {
 			_shortops.Add(new OperatorSignature("*", 2), new op_mul_2());
-			_shortops.Add(new OperatorSignature("&", 2), new op_mul_2());
 			_shortops.Add(new OperatorSignature("/", 2), new op_div_2());
 			_shortops.Add(new OperatorSignature("%", 2), new op_mod_2());
 
 			_shortops.Add(new OperatorSignature("+", 1), new op_add_1());
 			_shortops.Add(new OperatorSignature("+", 2), new op_add_2());
-			_shortops.Add(new OperatorSignature("|", 2), new op_add_2());
 			_shortops.Add(new OperatorSignature("-", 1), new op_sub_1());
 			_shortops.Add(new OperatorSignature("-", 2), new op_sub_2());