| i→n(i) = # fillsgn(i→n(i) + 1, int2bits(j % 2 ^ i)).rest, 2 ^ i ≤ j, 0 ≤ 2 ^ (i - 1) + j, 2 ^ (i - 1) ≤ j, 0 ≤ j, 0 < i, 2 ^ (i - 1) ≤ j % 2 ^ i ⊦ j % 2 ^ i = 2 ^ i + bits2int(fillsgn(i→n(i) + 1, int2bits(j % 2 ^ i)).rest) |
⊦ n ≤ # bits → fillsgn(n, bits) = bits
¬ i→n(i) + 1 ≤ # int2bits(j % 2 ^ i), i→n(i) = # fillsgn(i→n(i) + 1, int2bits(j % 2 ^ i)).rest, 2 ^ i ≤ j, 0 ≤ 2 ^ (i - 1) + j, 2 ^ (i - 1) ≤ j, 0 ≤ j, 0 < i, 2 ^ (i - 1) ≤ j % 2 ^ i ⊦ j % 2 ^ i = 2 ^ i + bits2int(fillsgn(i→n(i) + 1, int2bits(j % 2 ^ i)).rest)
i→n(i) + 1 ≤ # int2bits(j % 2 ^ i), i→n(i) = # int2bits(j % 2 ^ i).rest, 2 ^ i ≤ j, 0 ≤ 2 ^ (i - 1) + j, 2 ^ (i - 1) ≤ j, 0 ≤ j, 0 < i, 2 ^ (i - 1) ≤ j % 2 ^ i ⊦ j % 2 ^ i = 2 ^ i + bits2int(int2bits(j % 2 ^ i).rest)
Used terms: int2bits(j % 2 ^ i), i→n(i) + 1