delete_restriction : (string -> unit)

SYNOPSIS

Removes a restriction semantics from a binder.

DESCRIBE

Recall that if B is a binder and RES_B a constant then

   associate_restriction("B", "RES_B")

will cause the parser and pretty-printer to support:

               ---- parse ---->
   Bv::P. B                       RES_B  P (\v. B)
              <---- print ----

This behaviour may be disabled by calling delete_restriction with the binder name ("B" in this example).

FAILURE

Fails if you attempt to remove one of the builtin restrictions. These are associated with the binders

  ["!","?","@","\\"]

Also fails if the named binder is not restricted, i.e., found as the first member of a pair on the list returned by binder_restrictions.

EXAMPLE

    associate_restriction("DURING","RES_DURING");
    () : unit

    --`DURING x::(m,n). p x`--;
    (--`DURING x ::(m,n). p x`--) : term

    - delete_restriction "DURING";
    () : unit

    --`DURING x::(m,n). p x`--;

    Exception raised at Parse_support.restr_binder:
    no restriction associated with "DURING"

SEEALSO  associate_restrictions,   binder_restrictions