data Zob 0 = [
  | boo { choo : int } 
]

data LL 0 = [
  | emp { }
  | con { lHead : Zob, lTail : LL }
]

constraint:
  env []
  lhs {v:int | true }
  rhs {v:int | emp = (if (1 < 2) then emp else emp) }
  id 1 tag []