if x > y : #PREMISES FOR THEN-ARM: # (x > y) max = x #PREMISES FOR ATTACHED PROOF, IF ANY: # (max == x) # (x > y) #PREMISES FOR NEXT LINE: # (max == x) # (x > y) else : #PREMISES FOR ELSE-ARM: # not (x > y) max = y #PREMISES FOR ATTACHED PROOF, IF ANY: # (max == y) # not (x > y) #PREMISES FOR NEXT LINE: # (max == y) # not (x > y) #PREMISES FOR NEXT LINE: # (((max == x) and (x > y)) or ((max == y) and not (x > y)))