ABSTRACT
A logical calculus aims at accounting for the correctness of arguments in that it generates a potential list of their valid forms. In this way, it also constructs a relation of inference (whose instances are the correct arguments) that is to reconstruct the pre-theoretical relation of following-from. Gentzenian calculi result from the fixation of inferential roles of logical constants plus the fixation of the structural properties of inference. They can be seen as axiomatic systems, the axioms of which are some basic inferential rules (argument forms) and the rules of derivation of which some are metainferential rules (metaargument forms), which in the prototypical case are the Gentzenian structural rules. Such a calculus generates theorematic arguments, which are those that the calculus proclaims as valid. The calculi may also be multiple-conclusion, in which case we reach the Gentzenian sequent calculus.
