until -package:numeric-prelude -package:util -package:hedgehog -package:yesod-paginator -package:elerea -package:sparse-linear-algebra -package:protolude -package:netwire -package:monad-loops 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.