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 Th137:
  for p,q,w,y,x holds ((((x | (y | (y | y))) | w) | ((q | q) | w)
) | ((w | (x | q)) | (w | (x | q)))) = (((w | (p | (p | p))) | (w | (x | q))) |
  (((x | q) | (x | q)) | (w | (x | q))))
proof
  let p,q,w,y,x;
  ((w | (x | q)) | (w | (x | q))) = (((x | (y | (y | y))) | w) | ((q | q)
  | w)) by Th73;
  hence thesis by Th73;
end;
