type_vars_acc

Type.type_vars_acc : hol_type -> hol_type list -> hol_type list

Returns the set of type variables in a type.

An invocation type_vars_acc ty A returns a list representing the set-theoretic union of the type variables occurring in ty and A.

Failure

Never fails.

Example

> type_vars_acc ((alpha --> beta) --> bool --> beta) [];
val it = [“:β”, “:α”]: hol_type list

Comments

Code should not depend on how elements are arranged in the result of type_vars_acc.

See also

Type.type_vars, Type.type_varsl, Type.type_var_in, Type.exists_tyvar, Type.polymorphic, Term.free_vars