Is closer than ever?
common_crawl_change= (0, 0, 0,
[
(neg|conversation_screen_is_active),
(key_clicked, key_z),
],
[
(get_player_agent_no, ":ag"),
(try_begin),
(eq, "$crawling", 1),
(assign, "$crawling", 0),
(else_try),
(assign, "$crawling", 1),
(try_end),
])...