until -package:numeric-prelude -package:util -package:hedgehog -package:faktory -package:LambdaHack -package:intro -package:base-prelude -package:free -package:ghc-lib-parser -package:base-compat -package:linear-base 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.