(* Title: HOL/IOA/meta_theory/Asig.thy
ID: $Id$
Author: Tobias Nipkow & Konrad Slind
Copyright 1994 TU Muenchen
Action signatures
*)
Asig = Option +
types
'a signature = "('a set * 'a set * 'a set)"
consts
actions,inputs,outputs,internals,externals
::"'action signature => 'action set"
is_asig ::"'action signature => bool"
mk_ext_asig ::"'action signature => 'action signature"
defs
asig_inputs_def "inputs == fst"
asig_outputs_def "outputs == (fst o snd)"
asig_internals_def "internals == (snd o snd)"
actions_def
"actions(asig) == (inputs(asig) Un outputs(asig) Un internals(asig))"
externals_def
"externals(asig) == (inputs(asig) Un outputs(asig))"
is_asig_def
"is_asig(triple) ==
((inputs(triple) Int outputs(triple) = {}) &
(outputs(triple) Int internals(triple) = {}) &
(inputs(triple) Int internals(triple) = {}))"
mk_ext_asig_def
"mk_ext_asig(triple) == (inputs(triple), outputs(triple), {})"
end