Admissibility, compatibility, and deducibility in first-order sequent logics

The paper is about the notions of admissibility and compatibility and their significance for deducibility in different sequent logics including first-order classical and intuitionistic ones both without and with equality and, possibly, with modal rules. Results on the coextensivity of the proposed sequent calculi with usual Gentzen and Kanger sequent calculi as well as with their equality and modal extensions are given.