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: