There are two forms of procedure declaration:
PROCEDURE id sig = B id
PROCEDURE id sig
where
id is an identifier, sig is a procedure signature, and
B is a block. In both cases, the type of id is the procedure
type determined by sig. The first form is allowed only in
modules; the second form is allowed only in interfaces.
The first form declares id as a procedure constant whose signature is sig, whose body is B, and whose environment is the scope containing the declaration. The parameter names are treated as if they were declared at the outer level of B; the parameter types and default values are evaluated in the scope containing the procedure declaration. The procedure name id must be repeated after the END that terminates the body.
The second form declares id to be a procedure constant whose signature is sig. The procedure body is specified in a module exporting the interface, by a declaration of the first form.