#const maxtime=3.

% G1
fluent(gateStatus).
action(push).
action(pull).

% G2, G3, G4
possVal(gateStatus, open).
possVal(gateStatus, shut).
possVal(gateStatus, broken).

% G5'
causesValue(push, gateStatus, shut, T) :- 
	time(T),
	valueOf(gateStatus, T, V), 
	V != broken,
	not happens(pull, T).
causesValue(push, gateStatus, broken, T) :- 
	time(T),
	happens(pull, T).

% G6'
causesValue(pull, gateStatus, open, T) :- 
	time(T),
	valueOf(gateStatus, T, V), 
	V != broken,
	not happens(push, T).
causesValue(pull, gateStatus, broken, T) :- 
	time(T),
	happens(push, T).

% G7
-valueOf(gateStatus, 0, broken).

% G8
happens(pull, 2).
happens(push, 2).

#hide.
#show valueOf/3.
#show happens/2.