diff --git a/Assets/Cryville/Common/Pdt/PdtVariableMemory.cs b/Assets/Cryville/Common/Pdt/PdtVariableMemory.cs
index 8f3db02..eaeed98 100644
--- a/Assets/Cryville/Common/Pdt/PdtVariableMemory.cs
+++ b/Assets/Cryville/Common/Pdt/PdtVariableMemory.cs
@@ -4,7 +4,7 @@ namespace Cryville.Common.Pdt {
 	/// <summary>
 	/// Span on the memory of a <see cref="PdtEvaluatorBase" />.
 	/// </summary>
-	public unsafe struct PdtVariableMemory {
+	public unsafe struct PdtVariableMemory : IEquatable<PdtVariableMemory> {
 		readonly byte* _ptr;
 		/// <summary>
 		/// The length of the span.
@@ -46,6 +46,14 @@ namespace Cryville.Common.Pdt {
 			for (int i = 0; i < length; i++)
 				dest[destOffset + i] = _ptr[i];
 		}
+		/// <inheritdoc />
+		public bool Equals(PdtVariableMemory obj) {
+			if (Type != obj.Type || Length != obj.Length) return false;
+			for (int i = 0; i < Length; i++) {
+				if (*(_ptr + i) != *(obj._ptr + i)) return false;
+			}
+			return true;
+		}
 		/// <summary>
 		/// Gets the memory of the span as a number.
 		/// </summary>
diff --git a/Assets/Cryville/Crtr/PdtEvaluator.cs b/Assets/Cryville/Crtr/PdtEvaluator.cs
index 4498a30..606f39f 100644
--- a/Assets/Cryville/Crtr/PdtEvaluator.cs
+++ b/Assets/Cryville/Crtr/PdtEvaluator.cs
@@ -164,6 +164,7 @@ namespace Cryville.Crtr {
 
 			_shortops.Add(new PdtOperatorSignature("frame_seq", 3), new func_frame_seq());
 			_shortops.Add(new PdtOperatorSignature("in_area", 1), new func_in_area());
+			_shortops.Add(new PdtOperatorSignature("is", 2), new func_is());
 		}
 		#region Operators
 #pragma warning disable IDE1006
@@ -346,6 +347,17 @@ namespace Cryville.Crtr {
 				hit.CopyTo(ret);
 			}
 		}
+		class func_is : PdtOperator {
+			public func_is() : base(2) { }
+			protected override unsafe void Execute() {
+				var op0 = GetOperand(0);
+				if (op0.Type == PdtInternalType.Error) throw new ArgumentException("Error");
+				var op1 = GetOperand(1);
+				if (op1.Type == PdtInternalType.Error) throw new ArgumentException("Error");
+				var ret = GetReturnFrame(PdtInternalType.Number, sizeof(float));
+				ret.SetNumber(op0.Equals(op1) ? 1 : 0);
+			}
+		}
 		#endregion
 		#region Contextual Functions
 		class func_screen_edge : PdtOperator {