Lellmann, BjornPattinson, Dirk2015-12-13September9783642333521http://hdl.handle.net/1885/82995We present unlabelled cut-free sequent calculi for Lewis' conditional logic and extensions, in both the languages with the entrenchment connective and the strong conditional. The calculi give rise to Pspace-decision procedures, also in the language with the weak conditional. Furthermore, they are used to prove the Craig interpolation property for all the logics under consideration, and yield a Pspace-decision procedure for a recently considered hybrid version of .Keywords: Craig interpolation; Sequent calculus; Biomineralization; Differentiation (calculus); Artificial intelligence201210.1007/978-3-642-33353-8_252016-02-24