until -package:numeric-prelude -package:language-bash -package:clash-prelude -package:extra -package:prelude-compat -package:basic-prelude -package:monad-loops -package:termonad -package:LambdaHack -package:base-compat package:dunai
Similar to Yampa's delayed switching. Loses a b in case of an
exception.
Run the first
msf until the second one produces
True
from the output of the first.