“…The existing notions of tractability mainly include strong polynomial tractability (SPT), polynomial tractability (PT), quasi-polynomial tractability (QPT), weak tractability (WT), (s, t)-weak tractability ((s, t)-WT), and uniform weak tractability (UWT). In recent years the study of algebraic and exponential tractability has attracted much interest, and a great number of interesting results have been obtained (see [31,32,33,43,9,44,38,39,6,5,21,36,45,15,2,26,37] and the references therein).…”