sub bill { say 'hi' };; bill;; hi *bill = sub { say 'bye' };; Subroutine main::bill redefined at (eval 8) line 1, line 3. bill;; bye $x = 'bill';; *{$x} = sub { say 'hi again' };; Subroutine main::bill redefined at (eval 11) line 1, line 6. bill;; hi again