  Conceiving of premises as collected into sets or multisets, instead of
sequences, may lead to triviality for classical and intuitionistic logic in
general proof theory, where we investigate identity of deductions. Any two
deductions with the same premises and the same conclusions become equal. In
terms of categorial proof theory, this is a consequence of a simple fact
concerning adjunction with a full and faithful functor applied to the
adjunction between the diagonal functor and the product biendofunctor, which
corresponds to the conjunction connective.
