%%% A very simple hmm
%%% - illustrating extended with abstract implemementation.
%%% 
%%% Developed in the PRISM system by Henning Christiansen, November 2006
%%% http://www.ruc.dk/~henning


values(s0,[s1+rattle,s2+rattle,stop+nothing]).

values(s1,[s0+rattle,s1+rattle,s4+crunch,stop+nothing]).

values(s2,[s0+rattle,s3+crunch,stop+nothing]).

values(s3,[s2+crunch,s3+rattle,s4+squeak,stop+nothing]).

values(s4,[s1+crunch,s3+squeak,s5+crunch,s6+rattle,stop+nothing]).

values(s5,[s4+crunch,s5+rattle,s6+squeak,stop+nothing]).

values(s6,[s4+rattle,s5+squeak,s6+rattle,stop+nothing]).

%% no set_ss as we know nothing specific
%% PRISM assumes even distribution when nothing is given


target(hmm,1).

hmm(S):- hmm(S,_).

hmm(S,Where):- hmm(S,s0,Where).

hmm(S,From,Final):-
    msw(From,Next+Sound),
    (Next=stop -> S=[], Final=From
     ;
     S=[Sound|Sx], hmm(Sx,Next,Final)).