This is meant to be a light post, posing a perhaps naive question. One of the hallmarks of computational proof theory is the association between arithmetic theories and complexity classes, in terms of their provably recursive functions. But is there a general rule for identifying the provably recursive functions of a class of induction invariants?
Linear inferences of size 7
In Anupam’s recent post, he introduced the linear inferences switch and medial. By computational search it had been shown that all linear inferences with 6 or fewer variables are derivable from these two inferences. He also gave an 8 variable linear inference which is not derivable from switch and medial and posed the question of…
‘Simple’ proofs of cut-elimination II: intuitionistic logic
Cut-elimination for intuitionistic logic has particular significance to proof theorists due to the constructive nature of the logic. Cut-free proofs give rise to significant computational information, including interpolants of implications and, in the case of predicate logic, witnesses of existentials. Moreover, the process of cut-elimination can itself be viewed as a computational process thanks to…
What proof mining is about, Part IV: Kohlenbach & friends
(Parts I, II, III) After the developments recounted at the end of the previous post, proof mining lay dormant for a number of years; and it was during this period that it got its current name, as per the suggestion of Dana Scott. It was not just a renaming, but a refinement of the concept:…
