Lemma round13_eq_assemble_general: forall i buf plaintext S0 S12 S13, S0 = mbed_tls_initial_add_round_key plaintext buf -> S12 = mbed_tls_enc_rounds i S0 buf 4 -> S13 = mbed_tls_fround S12 buf (4 + 4 * Z.of_nat i) -> S13 = mbed_tls_enc_rounds (S i) (mbed_tls_initial_add_round_key plaintext buf) buf 4.