Gave tighter priorities to if, napply and the let-forms to
reduce ambiguities.
FOL: First-Order Logic with Natural Deduction
This directory contains the Standard ML sources of the Isabelle system for
First-Order Logic (constructive and classical versions). For a classical
sequent calculus, see LK. Important files include
ROOT.ML -- loads all source files. Enter an ML image containing Pure
Isabelle and type: use "ROOT.ML";
Makefile -- compiles the files under Poly/ML or SML of New Jersey
ex -- subdirectory containing examples. To execute them, enter an ML image
containing FOL and type: use "ex/ROOT.ML";
Useful references on First-Order Logic:
Antony Galton, Logic for Information Technology (Wiley, 1990)
Michael Dummett, Elements of Intuitionism (Oxford, 1977)