until -package:numeric-prelude -package:language-bash -package:clash-prelude -package:utility-ht -package:rebase -package:ghc-lib-parser -package:singletons-base -package:llvm-hs-pure -package:netwire -package:IfElse -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.