“…In subsequent works, permutable semigroups close to commutative ones (e.g., duo semigroups [10], medial semigroups [11], LC -commutative semigroups [12], RDGC n -commutative semigroups [13], etc. ), permutable completely regular semigroups (see Theorems 4.8 and 4.9 in [6]), and regular ω-semigroups [14] were studied.…”