is_type : hol_type -> bool

SYNOPSIS
Tests whether a type is an instance of a type constructor.

DESCRIPTION
is_type ty returns true if ty is a base type or constructed by an outer type constructor, and false if it is a type variable.

FAILURE CONDITIONS
Never fails.

EXAMPLE
  # is_type `:bool`;;
  val it : bool = true

  # is_type `:bool->int`;;
  val it : bool = true

  # is_type `:Tyvar`;;
  val it : bool = false

SEE ALSO
get_type_arity, is_vartype.