Ge1:= pl5 > REF(PL5, 1) and REF(PL5,1) < = ref (pl5,2) and ref (pl5,2) < =REF(PL5,3);
ex 1:= PL5 & lt; REF(PL5, 1) and REF(PL5,1) > = ref (pl5,2) and ref (pl5,2) > = ref (pl5,3);
Some functions of Yimeng software are irreplaceable by Tongda letter.
It is in this formula, so it cannot be rewritten.