theorem
  (.I \/ J.> = (.I "\/" J.>
proof
A1: (.I"\/"J.> = <.(I"\/"J).:.) by Th36;
  (.I \/ J.> = <.(I \/ J).:.) & I.:"/\"J.: = I"\/"J by Th36,Th44;
  hence thesis by A1,FILTER_0:37;
end;
