| i0 < 0 ∧ j < 0 ∧ abs(j) < 2 ^ (16 - 1) ∧ 0 < 16, # int2bits(j) ≤ 16, abs(j) < 2 ^ 16, ~32768 ≤ j, i0 * 2 ^ 16 + j < ~32768, j ≤ 0, i0 ≤ 0, i0 * 2 ^ 16 + j < 0 ⊦ s2i(i2s(bits2int(lastn(16, int2bits(i0 - 1) + fillsgn(i→n(16), int2bits(j)))))) = j |
~32768 < j, # int2bits(j) ≤ 16, ~32768 ≤ j, 65536 * i0 + j < ~32768, 65536 * i0 + j < 0, i0 < 0, j < 0 ⊦ s2i(i2s(bits2int(lastn(16, int2bits(i0 - 1) + fillsgn(16, int2bits(j)))))) = j
Used simplifier rules: ⊦ j < i ∧ i ≤ 0 → j < 0; (forward)% ⊦ i * j = j * i;% ⊦ i < 0 ∧ 0 ≤ j → i ≤ j;%i0 ≠ 0, i0 < i ⊦ (* i) < j → (* i0) < j;% ⊦ i + j = j + i;% ⊦ i + j + i0 = (i + j) + i0;% ⊦ (* j) < i0 + (* j0) ↔ j - j0 < i0;% ⊦ ~ i < j ↔ 0 < j + i;% ⊦ i < 0 → abs(i) = ~ i;