src/ZF/README

+		ZF: Zermelo-Fraenkel Set Theory
+
+This directory contains the Standard ML sources of the Isabelle system for
+ZF Set Theory.  It is loaded upon FOL, not Pure Isabelle.  Important files
+include
+
+ROOT.ML -- loads all source files.  Enter an ML image containing FOL 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 ZF and type:    use "ex/ROOT.ML";
+
+Useful references on ZF set theory:
+
+	Paul R. Halmos, Naive Set Theory (Van Nostrand, 1960)
+
+	Patrick Suppes, Axiomatic Set Theory (Dover, 1972)
+
+	Keith J. Devlin,
+	Fundamentals of Contemporary Set Theory (Springer, 1979)