PROGRAM "vero"

LOAD "cal.pl"

CAPABILITIES {
// Mental actions 
{True} Goal(Y) {goal(Y)}
{True} Pay(X,Y) {payed(X,Y)}
{TRUE} Treatedgo(X) {go(X)}
{True} Treated(X,C,Y) {not received(X,propose,content(price(C,Y)))}
{TRUE} Updateoffer(Z,W,N) {not currentoffer(Z), not lastoffer(W), lastoffer(Z), currentoffer(N)}
{TRUE} Updateotheroffer(X,Y) {not otheroffer(X), otheroffer(Y)}
{TRUE} Updatecheaper(Y,V) {not cheaper(V,Y), cheaper(Y,V)}
}
BELIEFBASE {
% domain knowledge
transport(rentcar).
transport(plane).
transport(train).
transport(boat).
conf(aaai).
conf(uumus).
conf(ijair).
pricereg(aaai,125).
pricereg(uumus,450).
pricereg(ijair,95).
town(sydney).
town(candera).
town(melbourne).
isin(aaai,sydney).
isin(uumus,candera).
isin(ijair,melbourne).
seller(philippe).
seller(sally).
seller(bob).
achieve(go(Z),W):- town(Z), transport(W). 
securetransport(X):- deal(price(Y,Z)), transport(Y).

% preferences

prefmin(rentcar,250).
prefmax(rentcar,100).
prefmin(plane,250).
prefmax(plane,150).


% beliefs about items-prices
cheapest(X):- not cheaper(Y,X).
cheaper(rentcar,plane).
cheaper(rentcar,train).
cheaper(rentcar,boat).

currentoffer(0).
lastoffer(0).
otheroffer(0).
% calculate the next offer
nextoffer(N):- currentoffer(Z), otheroffer(O), plus(Z,O,P), times(P,0.5,N).
% indicate when a deal has been reached
deal(price(C,Z)):- sent(X,accept,content(price(C,Z))), seller(X).
deal(price(C,Z)):- received(X,accept,content(price(C,Z))), seller(X).

}

GOALBASE {

go(aaai)
}

PLANBASE{}

PG-RULES{
//Plan to go to a conference
go(X)<- conf(X) and isin(X,Y)| {Goal(go(Y)); goal(go(Y)); payreg(X); Treatedgo(X);},
}

PR-RULES {
// initial plan for going somewhere
goal(X)<-  achieve(X,Z) and cheapest(Z) | {negotiate(Z)}
// initial plan for paying a registration
payreg(X)<- pricereg(X,Y) and securetransport(X) and not payed(X,Y)| {Pay(X,Y)},
negotiate(Z) <- seller(X) | {Send(X,request,content(Z)); bargain(X,Z)}
bargain(X,Content) <- received(X,propose,content(price(Content,Y))) and prefmin(Content,M) and prefmax(Content,P) and otheroffer(T) and currentoffer(C) | {Treated(X,Content,Y); Updateotheroffer(T,Y); minus(Y,C,D)?; if D < 10 then Send(X,accept,content(price(Content,Y))) else {nextoffer(X,Content); bargain(X,Content)}}
,
bargain(X,Y) <- received(X,reqpurpose,why(Y)) and achieve(Z,Y) and goal(Z) and not sent(X,inform,because(Z)) |{Send(X,inform,because(Z));argue(Z,Y)}
,
bargain(X,Y) <- received(X,reqpurpose,why(Y)) and achieve(Z,Y) and goal(Z) and sent(X,inform,because(Z)) | {Send(X,refuse,because(Z))},
bargain(X,Y) <- received(X,accept,content(price(Y,Z))) | {Treated(X,Y,Z)},
argue(Z,V) <- received(X,inform,content(achieve(Z,Y))) and goal(Z) and not cheaper(Y,V) | {Updatecheaper(Y,V); goal(Z)}
,
// accept the offer or generate a new one
nextoffer(Y,X)<- prefmin(X,M) and prefmax(X,A) and currentoffer(Z) and lastoffer(W) | {if not sent(Y,propose,content(price(X,A))) then {Send(Y,propose,content(price(X,A))); Updateoffer(Z,W,A)} else {nextoffer(N)?;  if N > M then {Send(Y,propose,content(price(X,M))); Updateoffer(Z,W,M)} else {Send(Y,propose,content(price(X,N))); Updateoffer(Z,W,N)}}}
,
}