| ⊦ m ≤ # buf0 + # buf1 → datasize(buf0 + buf1, m) = (m ≤ # buf0 ∨ datasize(buf1, m - # buf0) = 0 ⊃ datasize(buf0, min(m, # buf0));# buf0 + datasize(buf1, m - # buf0)) |
m ≤ # buf0 + # buf1 ⊦ datasize(buf0 + buf1, m) = (m ≤ # buf0 ∨ datasize(buf1, m - # buf0) = 0 ⊃ datasize(buf0, min(m, # buf0));# buf0 + datasize(buf1, m - # buf0))