reserve L for satisfying_Sh_1 non empty ShefferStr;
reserve L for satisfying_Sheffer_1 satisfying_Sheffer_2 satisfying_Sheffer_3
  non empty ShefferStr;
reserve v,q,p,w,z,y,x for Element of L;

theorem Th96:
  for p,w holds p = ((w | w) | p) | (((w | w) | (w | w)) | p)
proof
  let p,w;
  (p | p) | (p | (w | (w | w))) = p by Th72;
  hence thesis by Th95;
end;
