(Simple = allowing one to substitute a value for a function call, and then continue.)
Any other way to restart? restart-case provides alternatives. (In an interactive system), "anonymous restarts" give an opportunity to specify prompting from the debugger: e.g. do you want to recompute the function with different args? do you want to return an specified value? [computed in the context of the restart-case..] e.g.
(restart-case <compute-this> (nil <restart1>)(nil <restart2>))gives 2 options.
named restarts (trivial example):
(restart-case (invoke-restart 'foo 3)
(foo (x) (+ x 1)))
It is possible to use find-restart to see if a handler exists, and even (recursively) if that restart could be restarted (etc).