ite tt "a" "b" : string
sine x : real
sine n : real
sine i : real
x + i : real
coe2.lean:30:8: error: type mismatch at application
  i + x
term
  x
has type
  real
but is expected to have type
  int
i + x : real
x + n : real
coe2.lean:37:8: error: type mismatch at application
  n + x
term
  x
has type
  real
but is expected to have type
  ℕ
n + x : real