% Defining the time constants
time(0..length).

% Defining fluents
fluent(loaded).
fluent(dead).
fluent(walking).

% Defining actions
action(load).
action(shoot).

% Representing action effects

holds(dead, T+1):- time(T), 
  occ(shoot, T), 
  holds(loaded, T).

holds(neg(loaded), T+1):- 
  time(T), occ(shoot, T).

holds(loaded, T+1) :- time(T), occ(load, T).

% Static law 
holds(neg(walking), T):- 
  time(T), holds(dead, T).

% The initial state
holds(loaded, 0). 
holds(neg(dead), 0).
holds(walking, 0).

% Defining fluent literals
literal(F):- fluent(F).
literal(neg(F)):- fluent(F).

% Contrary literals
contrary(F, neg(F)):- fluent(F).
contrary(neg(F), F):- fluent(F).

% The inertial rule
holds(F, T+1) :- literal(F), time(T), 
     holds(F, T), contrary(G, F),
     not holds(G, T+1).

% action occurrences 
occ(shoot, 0).


%hide fluent(X).
hide action(A).
hide time(T). 
hide literal(L).
hide contrary(X,Y).