doc-src/Logics/abstract.txt

- record_split_tac now also works for object-level universal quantifier
- bound variables in split rule now have nicer names
- added new simproc record_eq_simproc which prevents simplifier
from choosing the "wrong" equality rule

Isabelle's Object-Logics.  Report 286.

This is the third of the Isabelle manuals.  It covers Isabelle's built-in
object logics: first-order logic (FOL), Zermelo-Fraenkel set theory (ZF),
higher-order logic (HOL), the classical sequent calculus (LK), and
constructive type theory (CTT).  The final chapter discusses how to define
new logics.  This manual assumes familiarity with Report 280, Introduction
to Isabelle.