L1 is a recursively enumerable language over Σ. An algorithm A effectively enumerates its words as w1, w2, w3, … Define another language L2 over Σ Union {#} as {wi # wj : wi, wj ∈ L1, i < j}. Here # is a new symbol. Consider the following assertions.
S1 : L1 is recursive implies L2 is recursive
S1 is correct can anyone explain how?
