diff --git a/prism/src/parser/ast/Expression.java b/prism/src/parser/ast/Expression.java
index 773a253e..60349183 100644
--- a/prism/src/parser/ast/Expression.java
+++ b/prism/src/parser/ast/Expression.java
@@ -649,6 +649,14 @@ public abstract class Expression extends ASTElement
 				&& ExpressionBinaryOp.isRelOp(((ExpressionBinaryOp) expr).getOperator());
 	}
 
+	/**
+	 * Test if an expression is a function of type {@code nameCode}.
+	 */
+	public static boolean isFunc(Expression expr, int nameCode)
+	{
+		return expr instanceof ExpressionFunc && ((ExpressionFunc) expr).getNameCode() == nameCode;
+	}
+
 	/**
 	 * Test if an expression is a quantitative property (P=?, R=? or S=?) 
 	 */