protocol
¶(protocol traversal ...)
or
(any traversal ...)
Try executing traversals, in order, until one succeeds (and then stop).
"Try going forward, if that doesn’t work try going backward."
(symex-eval (symex-traversal (any (move forward) (move backward))))
"Try going forward and up, if that doesn’t work try going backward and down."
(symex-eval (symex-traversal (any (do (move forward) (move up)) (do (move backward) (move down)))))