reserve A,B,O for Ordinal,
        o for object,
        x,y,z for Surreal,
        n,m for Nat;
reserve d,d1,d2 for Dyadic;
reserve i,j for Integer,
        n,m,p for Nat;
reserve r,r1,r2 for Real;

theorem Th47:
  uReal.0 = 0_No
proof
  thus uReal.0 = uDyadic.0 by Th46
  .= uInt.0 by Def5
  .=0_No by Def1;
end;
