where tl < t2 < .-- < t~ are points in a time scale "r with tl E "f,~, t~ E ~2~; A is the delta
derivative and V is the nabla derivative; n E N with n > 3; 7/> 0 and c~i >_ 0, for i E {2,..., n-l}
n-1 with 0 < Y";~i=2 c~i < 1. For example, if '11" = ~, (1) becomes the central difference equation