We show that the category proposed in [5] of logic system presentations equipped with cryptomorphisms gives rise to a category of parchments that is both complete and translatable to the category of institutions, improving
on previous work [15]. We argue that limits in this category of parchments constitute a very powerful mechanism for combining
logics.
This work was partially supported by FCT and FEDER, namely, via the Project FibLog POCTI/MAT/37239/2001, and the QuantLog
initiative of CLC.