Dictionary.net

A generic theorem prover with support forseveral object-logics, developed by Lawrence C. Paulson in collaboration with TobiasNipkow (http://in.tum.de/~nipkow/) at the TechnicalUniversity of Munich.A system of type classes allows polymorphic object-logicswith overloading and automatic type inference.Isabelle supports first-order logic - constructive andclassical versions; higher-order logic, similar to Gordon'sHOL; Zermelo Fränkel set theory; an extensional versionof Martin Löf's type theory, the classical first-ordersequent calculus, LK; the modal logics T, S4, andS43; and Logic for Computable Functions.An object logic's syntax and inference rules are specifieddeclaratively allowing single-step proof construction.Proof procedures can be expressed using "tactics" and"tacticals". Isabelle provides control structures forexpressing search procedures and generic tools such assimplifiers and classical theorem provers which can be appliedto object-logics. Isabelle is built on top of Standard MLand uses its user interface. (http://cl.cam.ac.uk/Research/HVG/Isabelle/).Mailing list: isabelle-users@cl.cam.ac.uk.["tactics"? "tacticals"?]