n` THEN0    (fs [flatSemTheory.do_app_def,list_case_eq,CaseEq "flatSem$v",PULL_EXISTS,            CaseEq "ast$lit",store_assign_def,option_case_eq]     \\ rw [] \\ fs [] \\ rveq \\ fs [LENGTH_EQ_NUM_compute] \\ rveq \\ fs []     \\ qpat_x_assum `v_rel (Loc _) _` mp_tac     \\ simp [Once v_rel_cases]     \\ fs [SWAP_REVERSE_SYM] \\ rw [] \\ fs [PULL_EXISTS]     \\ fs [compile_op_def,evaluate_def,do_app_def]     \\ fs [pair_case_eq,result_case_eq] \\ rveq \\ fs []     \\ 