rator : term -> term

SYNOPSIS
Returns the operator from a combination (function application).

DESCRIPTION
rator(`t1 t2`) returns `t1`.

FAILURE CONDITIONS
Fails with rator if term is not a combination.

EXAMPLE
  # rator `f(x)`;;
  Warning: inventing type variables
  val it : term = `f`

  # rator `~p`;;
  val it : term = `(~)`

  # rator `x + y`;;
  val it : term = `(+) x`

SEE ALSO
dest_comb, lhand, lhs, rand.