reserve X,Y,Z,X1,X2,Y1,Y2 for set, x,y,z,t,x1,x2 for object,
  f,g,h,f1,f2,g1,g2 for Function;

theorem Th36:
  uncurry {} = {} & uncurry' {} = {}
proof
A1: now
    set t = the Element of dom uncurry {};
    assume dom uncurry {} <> {};
    then ex x,g,y st t = [x,y] & x in dom {} & g = {} .x & y in dom g by Def2;
    hence contradiction;
  end;
  hence uncurry {} = {};
  thus thesis by A1,Th1,RELAT_1:41;
end;
