% SZS status Theorem for opp__d
% SZS output start Proof for opp__d
  file('i/f/ring/opp__def',ah4s_rings_isu_u_ringu_u_def)).
  file('i/f/ring/opp__def',ch4s_rings_oppu_u_def)).
% SZS output end Proof for opp__d
