set I = goto 0;
let W be Instruction of SCMPDS; ( W is halting implies W = goto 0 )
assume A1:
W is halting
; W = goto 0
assume A2:
goto 0 <> W
; contradiction
per cases
( ex k1 being Integer st W = goto k1 or ex a being Int_position st W = return a or ex a being Int_position ex k1 being Integer st W = saveIC (a,k1) or ex a being Int_position ex k1 being Integer st W = a := k1 or ex a being Int_position ex k1, k2 being Integer st W = (a,k1) := k2 or ex a being Int_position ex k1, k2 being Integer st W = (a,k1) <>0_goto k2 or ex a being Int_position ex k1, k2 being Integer st W = (a,k1) <=0_goto k2 or ex a being Int_position ex k1, k2 being Integer st W = (a,k1) >=0_goto k2 or ex a, b being Int_position ex k1, k2 being Integer st W = AddTo (a,k1,k2) or ex a, b being Int_position ex k1, k2 being Integer st W = AddTo (a,k1,b,k2) or ex a, b being Int_position ex k1, k2 being Integer st W = SubFrom (a,k1,b,k2) or ex a, b being Int_position ex k1, k2 being Integer st W = MultBy (a,k1,b,k2) or ex a, b being Int_position ex k1, k2 being Integer st W = Divide (a,k1,b,k2) or ex a, b being Int_position ex k1, k2 being Integer st W = (a,k1) := (b,k2) )
by Th91;
end;