“…Many articles such us [1], [3], [6], [8], [9], [10] introduced approximation theorems interims of the ordinary modulus of smoothness, with ordinary symmetric difference. Here we shall define new symmetric difference, then we use it to obtain anew modulus of smoothness and πΎ β ππ’πππ‘πππππ, in anew quasi normed spaces, call it πΏ π,π½ .…”