Progress Rules

• (if #f
  (if V if #f
• (cond [#f E] (cond )
  (cond [V E] if #f
  (cond [else E]
• ( )
  if primitive
  if ((lambda ( ) E) )
  where the notation means to substitute the value for the name in expression E.
• (define n undefined
• (local [(define ) (define )] see Section 6.1