const length = 2.

:- not trans(test,0,2).

% the action theory  
% causes(a1, f, [neg(f)].
% causes(a2, p, [neg(g), f]).
% causes(a3, p, [g, f]).
% causes(a,  p, [neg(p)]).

% initially(neg(f)).
% initially(g).    
% initially(neg(p)).

% action(a1).
% action(a2).
% action(a3).
% action(a).

% fluent(f).
% fluent(g).
% fluent(p).

% a1; while (neg(p)) do a2 $ a3 $ a $ null; p? 

proc(test).
head(test, a1).
tail(test, two).

proc(two).
head(two, w).
tail(two, p).

while(w, neg(p), n1).

choiceAction(n1).
in(a2, n1).
in(a3, n1).
in(a, n1).
in(null, n1).