| #(buf0 + buf1) = #(buf2 + buf3), n + 1 < # buf0, # buf2 < # buf0, n < # buf2, n < # buf0, is-encoded(b, buf2), is-encoded(a, buf0), ∀ n. n < #(buf0 + buf1) → (buf0 + buf1)[n] = (buf2 + buf3)[n] ⊦ # buf0 = # buf2, buf0[n] = buf2[n], is-encoded(b, subarray(buf0, 0, # buf2)) |
# buf0 + # buf1 = # buf2 + # buf3, n < # buf0, n < # buf2, # buf2 < # buf0, n + 1 < # buf0, is-encoded(a, buf0), is-encoded(b, buf2), ∀ n0. n0 < # buf2 + # buf3 → (buf0 + buf1)[n0] = (buf2 + buf3)[n0] ⊦ # buf0 = # buf2, buf0[n] = buf2[n], is-encoded(b, subarray(buf0, 0, # buf2))
Used simplifier rules: append-a: ⊦ (buf + buf0) + buf1 = buf + buf0 + buf1; from specification array-splice[buffer]% ⊦ #(buf + buf0) = # buf + # buf0; (s)