“…Motivated by [27], we proposed some conditions on activation functions to set up existence criterion for the equilibrium solution of system (4). In [22,23], the constant equilibrium solution = * for all ∈ [ 0 , +∞) was obtained by homomorphic mapping theory and matrix theory, or matrix theory and homotopy invariance theorem, where * = ( * 1 , * 2 , . .…”