Anything foldable ∘ anything foldable → optics.ForgetFold over List. Fires only when no total/partial instance applies, i.e. at least one side is genuinely multi-focus (MultiFocus[F] / Forget[F]).
Anything foldable ∘ anything foldable → optics.ForgetFold over List. Fires only when no total/partial instance applies, i.e. at least one side is genuinely multi-focus (MultiFocus[F] / Forget[F]).