% FallingObjectWithAntiTrajectory-15.fo

time(0..maxstep).
offset(1..10).
height(0..10).
agent(nathan).
object(apple).

#domain object(Ob).
#domain height(H;H1;H2).
#domain agent(A).
#domain time(T).
#domain offset(Off).

fluent(falling(Ob);height(Ob,H)).
event(drop(A,Ob);hitGround(Ob)).

% Sigma

initiates(drop(A,Ob),falling(Ob),T).

terminates(hitGround(Ob),falling(Ob),T).

% Delta
holdsAt(falling(Ob),T) &
holdsAt(height(Ob,0),T) ->
happens(hitGround(Ob),T).

happens(drop(nathan,apple),0).

% Psi

holdsAt(height(Ob,H1),T) &
holdsAt(height(Ob,H2),T) ->
H1=H2.

% Pi

holdsAt(height(Ob,H1),T) &
H2 = (H1 - Off) ->
trajectory(falling(Ob),T,height(Ob,H2),Off).

holdsAt(height(Ob,H),T) ->
antiTrajectory(falling(Ob),T,height(Ob,H),Off).

% Gamma

-holdsAt(falling(apple),0).
holdsAt(height(apple,10),0).

-releasedAt(falling(Ob),0).

releasedAt(height(Ob,H),0).

% End of file.