37 lines
1.2 KiB
Plaintext
37 lines
1.2 KiB
Plaintext
|
#const horizon=1.
|
||
|
|
||
|
% Check feature requirements
|
||
|
:- requires(feature(actionCosts)).
|
||
|
:- requires(feature(axiomRules)).
|
||
|
:- requires(feature(conditionalEffects)).
|
||
|
|
||
|
% Horizon, must be defined externally
|
||
|
time(0..horizon).
|
||
|
|
||
|
% Establish initial state
|
||
|
holds(Variable, Value, 0) :- initialState(Variable, Value).
|
||
|
|
||
|
% Perform actions
|
||
|
1 {occurs(Action, T) : action(Action)} 1 :- time(T), T > 0.
|
||
|
|
||
|
% Check preconditions
|
||
|
:- occurs(Action, T), precondition(Action, Variable, Value), not holds(Variable, Value, T - 1), time(T), time(T - 1).
|
||
|
|
||
|
% Apply effects
|
||
|
caused(Variable, Value, T) :- occurs(Action, T), postcondition(Action, _, Variable, Value).
|
||
|
modified(Variable, T) :- caused(Variable, Value, T).
|
||
|
|
||
|
holds(Variable, Value, T) :- caused(Variable, Value, T), time(T).
|
||
|
holds(Variable, Value, T) :- holds(Variable, Value, T - 1), not modified(Variable, T), time(T), time(T - 1).
|
||
|
|
||
|
% Check that variables have unique values
|
||
|
:- variable(Variable), not 1 {holds(Variable, Value, T) : contains(Variable, Value)} 1, time(T).
|
||
|
|
||
|
% Check mutexes
|
||
|
:- mutexGroup(MutexGroup), not {holds(Variable, Value, T) : contains(MutexGroup, Variable, Value)} 1, time(T).
|
||
|
|
||
|
% Verify that goal is met
|
||
|
:- goal(Variable, Value), not holds(Variable, Value, horizon).
|
||
|
|
||
|
#show occurs/2.
|