maybeShouldObeyMonadLaws(
  "looking up Numbers and Registrations by Name",
  lookup.names,
  lookup.lookupNumber _,
  lookup.lookupRegistration _)

maybeShouldObeyMonadLaws(
  "looking up Registrations and TaxesOwed by Number",
  lookup.numbers,
  lookup.lookupRegistration _,
  lookup.lookupTaxOwed _)