“…Note that, in contrast with the scalar case, the usual forms of the maximum principle do not hold, in general, for systems -for a simple counterexample we refer to [9]. However, maximum principles for parabolic systems as (1.1) are available when f (t, x, u, v, ξ) and g(t, x, u, v, ξ) are nondecreasing functions in each of the (u, v)-variables (see [9]). When applicable, approaches based on maximum principles can yield global existence results for nonlinearities with superlinear growth (see [9] and references therein).…”