* Added annihilation axioms ("x * 0 = 0") to axclass semiring_0.
Richer structures do not inherit from semiring_0 anymore, because
anihilation is a theorem there, not an axiom.
* Generalized axclass "recpower" to arbitrary monoid, not just
commutative semirings.
(*  Title:      HOL/IOA/ROOT.ML
    ID:         $Id$
    Author:     Tobias Nipkow & Konrad Slind
    Copyright   1994  TU Muenchen
This is the ROOT file for the meta theory of I/O-Automata.
@inproceedings{Nipkow-Slind-IOA,
author={Tobias Nipkow and Konrad Slind},
title={{I/O} Automata in {Isabelle/HOL}},
booktitle={Proc.\ TYPES Workshop 1994},
publisher=Springer,
series=LNCS,
note={To appear}}
ftp://ftp.informatik.tu-muenchen.de/local/lehrstuhl/nipkow/ioa.ps.gz
and
@inproceedings{Mueller-Nipkow,
author={Olaf M\"uller and Tobias Nipkow},
title={Combining Model Checking and Deduction for {I/O}-Automata},
booktitle={Proc.\ TACAS Workshop},
organization={Aarhus University, BRICS report},
year=1995}
ftp://ftp.informatik.tu-muenchen.de/local/lehrstuhl/nipkow/tacas.dvi.gz
*)
use_thy "Solve";