ZF/Inductive.thy,.ML: renamed from "inductive" to allow re-building without the keyword "inductive" making the theory file fail ZF/Makefile: now has Inductive.thy,.ML ZF/Datatype,Finite,Zorn: depend upon Inductive ZF/intr_elim: now checks that the inductive name does not clash with existing theory names ZF/ind_section: deleted things replicated in Pure/section_utils.ML ZF/ROOT: now loads Pure/section_utils