## 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)