“…The viscosity approximation method is known to yield strong convergence sequences and most importantly, it performs better numerically than many other iterative methods such as the Mann, Ishikawa, Hybrid and Halpern iterative schemes for approximating the fixed point of nonlinear mappings. More so, the viscosity approximation method was incorporated for solving many optimization problems; see, e.g., [12][13][14][15][16]. Recently, the viscosity method was extended to CAT(0) spaces for approximating the fixed point of other nonlinear mappings such as strictly nonexpansive, pseudocontractive, nonspreading, and demicontractive mappings; see [12][13][14][15][16][17].…”