Answer:
Free Semigroup: Consider a non empty set A = {a 1,a 2,.....a n }. Now, A* is the set of all finite sequences of elements of A, i.e., A* consist of all words that can be formed from the alphabet of A. If α,β,and,γ are any elements of A*, then α, (β. γ)= (α.β).γ.
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