diff -r eec72263ed75 -r 569bf5707c7e compiler/extensions.st
--- a/compiler/extensions.st	Mon Sep 14 11:19:10 2015 +0100
+++ b/compiler/extensions.st	Mon Sep 14 15:03:03 2015 +0100
@@ -98,6 +98,14 @@
     "Created: / 02-09-2015 / 06:30:30 / Jan Vrany <jan.vrany@fit.cvut.cz>"
 ! !
 
+!RBProgramNode methodsFor:'testing'!
+
+isSpecialFormNode
+    "return false here; to be redefined in subclass(es)"
+
+    ^ false
+! !
+
 !RBProgramNode methodsFor:'accessing'!
 
 scope