## Sequents: Various Sequent Calculi

This directory contains the ML sources of the Isabelle system for various Sequent, Linear, and Modal Logic.

The subdirectories `ex`, `ex/LK`, `ex/ILL`, `ex/Modal` contain some examples.

Much of the work in Modal logic was done by Martin Coen. Thanks to Rajeev Gore' for supplying the inference system for S43. Sara Kalvala reorganized the files and supplied Linear Logic. Jacob Frost provided some improvements to the syntax of sequents.

Useful references on sequent calculi:

- Steve Reeves and Michael Clarke,
  Logic for Computer Science (Addison-Wesley, 1990)
- G. Takeuti,
  Proof Theory (North Holland, 1987)

Useful references on Modal Logics:

- Melvin C Fitting,
  Proof Methods for Modal and Intuitionistic Logics (Reidel, 1983)
- Lincoln A. Wallen,
  Automated Deduction in Nonclassical Logics (MIT Press, 1990)

Useful references on Linear Logic:

- A. S. Troelstra
  Lectures on Linear Logic (CSLI, 1992)
- S. Kalvala and V. de Paiva
  Linear Logic in Isabelle (in TR 379, University of Cambridge Computer Lab, 1995, ed L. Paulson)