reserve v for object;
reserve V,A for set;
reserve f for SCBinominativeFunction of V,A;
reserve d for TypeSCNominativeData of V,A;
reserve d1 for NonatomicND of V,A;
reserve a,b,c,z for Element of V;
reserve x,y for object;
reserve p,q,r,s for SCPartialNominativePredicate of V,A;

theorem Th10:
  for x,y being ExtReal holds
   not x less_pred y implies y less_pred x or x = y
  proof
    let x,y be ExtReal;
    assume not x less_pred y & not y less_pred x;
    then x <= y & x >= y;
    hence thesis by XXREAL_0:1;
  end;
