• the line at time t = i
• the tab at time t = j
• statement at line i, tab j = if expr:
• Expression Stack at time t = [ [ ], [ ] ]
• Value Stack at time t = [ [ False, [ ] ], [ ] ]

then Control Map at time (t + 1) = result of storing (pair ("if", False)) at key: j in map: (Control Map at time t)