 But proponents of particular alternative views about the meanings of the logical constants might instead hold that they can make good sense of difference in meaning in these contexts, and that Carnap has simply endorsed the wrong theory of meaning and as a result drawn the wrong conclusions for logic. One specific issue that they might point to is associated with Prior’s 1960 paper “The Runabout Inference Ticket”, in which he provides rules for a new connective, tonk, which quickly lead to triviality, suggesting that he was not quite “at liberty to build his own logic” by introducing rules for his expressions. Another issue is the fact that one can generate different logics, not by varying the rules governing any particular expression, but rather by varying the more general structural rules of the logic, which govern things like whether or not one is allowed multiple conclusions, and whether or not a premise can be used more than once in a proof (Restall 2000; Paoli 2003). This suggests that even if the meanings of the logical expressions are governed by the rules that tell you how they can be used in proofs (as Carnap suggests) two logics can agree on those rules, whilst disagreeing on the relation of logical consequence. Hence even if you have successfully chosen a language, it seems that you might not yet have determined a logic. 