until -package:numeric-prelude -package:util -package:hedgehog -package:yesod-paginator -package:protolude -package:intro -package:LambdaHack -package:linear-base -package:numhask -package:base-prelude 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.