| buf0 + buf1 = buf2 + buf3, is-encoded(a, buf0), # buf0 ≤ # buf2 ⊦ is-encoded(b, buf2) ↔ # buf0 = # buf2 ∧ a = b |
⊦ is-encoded(a, buf) ∧ n ≤ # buf → (is-encoded(b, subarray(buf, 0, n)) ↔ b = a ∧ n = # buf)
buf0 + buf1 = buf2 + buf3, is-encoded(a, buf0), # buf0 ≤ # buf2, is-encoded(b, buf2) ∧ # buf0 ≤ # buf2 → (is-encoded(a, subarray(buf2, 0, # buf0)) ↔ a = b ∧ # buf0 = # buf2) ⊦ is-encoded(b, buf2) ↔ # buf0 = # buf2 ∧ a = b
Used terms: b, buf2, # buf0, a