languages Definition Language Concatenation Let L1,L2 be two languages, then: L1⋅L2={w1⋅w2∣w1∈∧ w2∈L2} Properties Associativity A⋅(B⋅C)=(A⋅B)⋅C Left-Distributivity A⋅(B∪C)=A⋅B∪A⋅C Right-Distributivity (B∪C)⋅A=B⋅A∪C⋅A