--- a/python/ir.py	Sun Sep 29 14:08:15 2013 +0200
+++ b/python/ir.py	Sat Oct 12 09:56:23 2013 +0200
@@ -274,6 +274,14 @@
     """ Convenience call """
     return Binop(a, '+', b)
 
+def Sub(a, b):
+    return Binop(a, '-', b)
+
+def Mul(a, b):
+    return Binop(a, '*', b)
+
+def Div(a, b):
+    return Binop(a, '/', b)
 
 class Eseq(Expression):
     """ Sequence of instructions where the last is an expression """
@@ -397,6 +405,8 @@
         return 'IF {} {} {} THEN {} ELSE {}'.format(self.a, self.cond, self.b, self.lab_yes, self.lab_no)
 
 
+# Constructing IR:
+
 class NamedClassGenerator:
    def __init__(self, prefix, cls):
       self.prefix = prefix