Compat.tyvarsl : (term list -> type list)

SYNOPSIS
Returns a list of the type variables free in a list of terms.

DESCRIBE
Found in the hol88 library. When applied to a list of terms, tyvarsl returns a list (possibly empty) of the type variables which are free in any of those terms.

FAILURE
Never fails. The function is not accessible unless the hol88 library has been loaded.

EXAMPLE
  - tyvarsl [--`!x. x = 1`--, --`!x:'a. x = x`--];
  [(==`:'a`==)] : hol_type list

USES
Finding all the free type variables in the assumptions of a theorem, as a check on the validity of certain inferences.

COMMENTS
tyvarsl does not appear in hol90. In the current HOL logic, there is no binding operation for types, so `is free in' is synonymous with `appears in'.

SEEALSO  tyvars

HOL  Kananaskis 0