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 Th136:
  for y,p,w holds (w | p) | (w | (y | (y | y))) = w
proof
  let y,p,w;
  w | w = (w | (y | (y | y))) by SHEFFER1:def 14;
  hence thesis by Th135;
end;
