added Induct/Binary_Trees.thy, Induct/Tree_Forest (converted from
former ex/TF.ML ex/TF.thy ex/Term.ML ex/Term.thy);
tutorial Tutorial on Isabelle/HOL
axclass Tutorial on Axiomatic Type Classes
isar-ref The Isabelle/Isar Reference Manual
ref The Isabelle Reference Manual
system The Isabelle System Manual
intro Introduction to Isabelle
logics Isabelle's Logics: overview and misc logics
logics-HOL Isabelle's Logics: HOL
logics-ZF Isabelle's Logics: FOL and ZF
ind-defs (Co)Inductive Definitions in ZF