opinion: DIAMOND, COMMISSIONER OF PATENTS AND TRADEMARKS v. BRADLEY et al.
  No. 79-855.
  Argued October 14, 1980
  Decided March 9, 1981
  Deputy Solicitor General Wallace argued the cause for petitioner. With him on the briefs were Solicitor General McCree, Assistant Attorney General Litvack, Harriet S. Shapiro, Robert B. Nicholson, Frederic Freilicher, Joseph F. Nakamura, and Thomas E. Lynch.
  Nicholas Prasinos argued the cause for respondents. With him on the briefs were Faith F. Driscoll, Henry L. Hanson, and Ronald T. Reiling.
  Edward S. Irons, Mary Helen Sears, and Robert P. Beshar filed a brief for National Semiconductor Corp. as amicus curiae urging reversal.
  Briefs of amici curiae urging affirmance were filed by Donald R. Dunner, Kenneth E. Kuffner, and Travis Gordon White for the American Patent Law Association, Inc.; by Reed C. Lawlor and James W. Geriak for the Los Angeles Patent Association; and by Morton C. Jacobs for Applied Data Research, Inc., et al.
  William James Beard and John F. Tregoning filed a brief for Halliburton Services as amicus curiae.
  Per Curiam.
  The judgment is affirmed by an equally divided Court.
  The Chief Justice ..took no part in the consideration or decision of this case.