“…Where π 1 (π₯, π‘, π¦ 1 , π¦ 2 , π¦ 3 ) = π 1 (π₯, π‘, π¦ 1 ) + π 2 (π₯, π‘, π¦ 2 )+π 3 (π₯, π‘, π¦ 3 ), and π 2 (π₯, π‘, π’ 1 , π’ 2 ) = β 1 (π₯, π‘, π’ 1 ) + β 2 (π₯, π‘, π’ 2 ) + β 3 (π₯, π‘, π’ 3 ), From the definition of the FD and the result of Theorem (2-(a)) [16] and from the assumptions on π π (βπ = 1,2,3), and then using the inequality of Minkowski once obtains:…”