@base <http://www.w3.org/2001/tag/dj9/>.
@prefix : <speech#>.

@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
@prefix dc: <http://purl.org/dc/elements/1.1/>.
@prefix s: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix owl: <http://www.w3.org/2002/07/owl#>.

<> dc:source _:ablp.
_:ablp
	 dc:title "A Calculus for Access Control in Distributed Systems";
	 dc:creator "Martin Abadi, Michael Burrows, Butler Lampson, and Gordon Plotkin";
	 dc:publisher "ACM";
	 s:comment "Trans. Programming Languages and Systems, 15, 4, pp 706-734.";
	 dc:date "1993-10";
	 s:seeAlso <http://research.microsoft.com/en-us/um/people/blampson/44-CalculusAccessControl/44-CalculusAccessControlAbstract.html>,
	 <http://research.microsoft.com/en-us/um/people/blampson/44-CalculusAccessControl/44-CalculusAccessControlAsPub.pdf> .

# ugh. there seem to be several related papers.
# these course notes look right
# http://www.ecs.syr.edu/faculty/chin/ACECS/Examples/example6a.pdf

# modal stuff

@prefix log: <http://www.w3.org/2000/10/swap/log#>.

:says s:label "says";
     s:domain :Principal.

# idemopotency?
{ ?A :says { ?A :says :s } } => { ?A :says ?s }.

:speaks_for s:label "speaks for";
	  s:isDefinedBy _:ablp;
	  s:domain :Principal;
	  s:range :Principal.

{ ?A :speaks_for ?B . ?A :says ?s } => { ?B :says ?s }.

{ ?A :says ?s. ?A :says { ?s => ?s2 }} => { ?A :says ?s2 }.

{ ?A :says { ?s => ?s2 } } => { { ?A :says ?s } => { ?A :says ?s2 } }.
{ ?A a :Principal. ?s a log:Truth } => { ?A :says ?s }.

:quoting a owl:FunctionalProperty;
         s:domain rdf:List; # of 2 principals
	 s:range :Principal.

#@@ <=> { [is quoting of (?B A)] :says s } <=> { ?B :says { A :says s }}.
#{ ?Q is quoting of (A B); :says s } => { A :says { B :says s } }.
# need this? { A :says { B :says s } } => { [ is quoting of (A B) ] :says s }.

# blows up in fwd chainer:
# { ?A :says ?p. ?A :says ?q. } => { ?A :says [ is log:conjunction of (?p ?q)]}.
{ ?A :says { ?subj ?pred ?obj }.
  ?A :says { ?subj2 ?pred2 ?obj2 }. } =>
   { ?A :says { ?subj ?pred ?obj. ?subj2 ?pred2 ?obj2 }}.

######

:controls s:label "controls";
         s:domain :Principal.

{ ?A :controls ?s . ?A :says ?s } => { ?s a log:Truth } . #level-breaker.

# constrained version of the rule:
{ ?A :controls_spo ( ?subj ?pred ?obj ) ;
   :says ?F. ?F log:includes { ?subj ?pred ?obj } }
 => { ?subj ?pred ?obj }.

# special case

:controls_property s:label "controls property";
  s:domain :Principal;
  s:range rdf:Property.

{ ?A :controls_property ?pred.
  ?A :says ?F. ?F log:includes { ?subj ?pred ?obj } } => { ?subj ?pred ?obj }.

#####
# Theorems to help cwm

#{ A :says { ?Q is quoting of (A B); :says s } } => { B :says s }.
# justification:
# { A | B :says S } => { A :says s } . # defn quoting
# A :says { { A | B :says S } => { A :says s } } # principals say all true things
# A :says { A :says s } # implication works inside :says
# A :says s # idemopotency of :says

# partial treatment of log:Truth
{ { ?subj ?pred ?obj } a log:Truth } => { ?subj ?pred ?obj }.

