“…To a large extent, the tedious deduction problems in qualitative analysis have been resolved and many encouraging results have been obtained regarding the stability analysis of dynamical systems [21,22,55], the determination of center conditions [41,46,53], the estimation of the number of limit cycles [10,19,50], the investigation of invariant algebraic curves [1,6,42], etc. More recent progress on symbolic computation methods for the qualitative theory of differential equations can be found in [23].…”