“…For example, the popular ANFIS model for T1 fuzzy systems [24] combines mathematical programming (least squares estimation) and a gradient-based algorithm in its optimization. EC algorithms are recommended for the optimization of IT2 fuzzy systems, because derivatives are difficult to compute in an IT2 fuzzy system (especially when the LMF and/or UMF formulas include tests about the location of their independent variable), and such algorithms are globally convergent [34], [4], [15], [44], [28]. There are many such EC algorithms, e.g., genetic algorithms, simulated annealing, particle swarm optimization, etc.…”