  In a recent paper, Wang. et al. (2009) claim that Tsallis' nonadditivity of
q-nonextensive statistical mechanics (Gell-Mann and Tsallis 2004, Tsallis 2009)
is mathematically inconsistent and hence one should carefully review Tsallis'
ideas and theory in toto. This present comment is to point out that the
conclusions of Wang et al. (2009) were arrived at by misinterpreting two basic
items and hence the advice of Wang et al. should be carefully reviewed.
