PROCEDURE <id> <sig> "="
<decls>
BEGIN
<stmts>
END <id> ";"
A procedure declaration is composed of an identifier, a signature (see section Procedure Types), optional local declarations, and statements. The identifier <id> at the end of the procedure must match the id at the beginning. Declarations made in a procedure are local to the procedure: they exist only while the procedure is executing.
If the procedure signature specifies a result type, the procedure is called a function procedure, and it must include a RETURN statement which returns an expression of the specified type. It is a checked runtime error for a function procedure to fail to return a result.