:@choice = 2

:f = "f"!script($_)
	| a |>
		|-> a
		#p!checkpoint
		| aa |>
			|-> aa
		| ab |>
			|-> ab
	| b |>
		|-> b
	choice = 2

	| c |>
		|-> c
	choice=1

| f:
f!

| f from #p:
f!from(#p)