This is a cryptology question from the book Introduction to Modern Cryptography by Katz and Lindell. If needed, please refer to the textbook's online pdf to answer the question. Please answer BOTH parts of the question fully, and with any necessary examples/proofs. Please show ALL steps and explain logic fully. Let (Gen; H) be a collision-resistant hash function and let F be a PRF. For each of the following, state whether H is necessarily collision resistant. Justify your answer. H^s (x_1 ||x_2): = H^s(x_1) || H^s(x_2) H^s(x_1||x_2): = H^s(x_1 x_2)