1:- op(100,fx,?). 2 3portray(#(PP,Pred,Trace,Adv)) :- 4 portray_bit(pp,PP,S0,S1), 5 portray_bit(pred,Pred,S1,S2), 6 portray_bit(trace,Trace,S2,S3), 7 portray_bit(adv,Adv,S3,[]), 8 write(S0). 9 10portray_bit(Bit,Value,[?Bit|Bits],Bits) :- var(Value), !. 11portray_bit(Bit,1,[Bit|Bits],Bits). 12portray_bit(Bit,0,Bits,Bits)