diff --git a/jenetics.prog/src/main/java/io/jenetics/prog/op/MathOp.java b/jenetics.prog/src/main/java/io/jenetics/prog/op/MathOp.java
index <HASH>..<HASH> 100644
--- a/jenetics.prog/src/main/java/io/jenetics/prog/op/MathOp.java
+++ b/jenetics.prog/src/main/java/io/jenetics/prog/op/MathOp.java
@@ -310,8 +310,23 @@ public enum MathOp implements Op<Double> {
 	 *
 	 * @see Math#tanh(double)
 	 */
-	TANH("tanh", 1, v -> tanh(v[0]));
+	TANH("tanh", 1, v -> tanh(v[0])),
 
+	/* *************************************************************************
+	 * Conditional functions
+	 * ************************************************************************/
+
+	/**
+	 * Returns +1.0 if its first argument is greater than its second argument
+	 * and returns -1.0 otherwise.
+	 *
+	 * @since !__version__!
+	 */
+	GT("gt", 2, v -> v[0] > v[1] ? 1.0 : -1.0);
+
+	/* *************************************************************************
+	 * Additional mathematical constants.
+	 * ************************************************************************/
 
 	/**
 	 * The double value that is closer than any other to pi, the ratio of the
#<I>: Add 'GT' function usable for Genetic Programming.