| b2i(bytes0.first) = ~1, 0 ≤ b2i((bytes0.rest + by ').first), false ∈ bytes2bits(bytes0), true ∈ bytes2bits(bytes0), ∀ bytes1. # bytes1 < #(bytes0 + by ') → b2i(bytes1.first) = ~1 ∧ 0 ≤ b2i(bytes1.rest.first) → bits2bytes(sgn(bytes2bits(bytes1))) = bytes1 ∨ # bytes1 = 1 ∨ bytes1 = [] ⊦ bytes0 = [], bits2bytes(sgn(bytes2bits(bytes0))) + i2b(bits2int(lastn(8, sgn(bytes2bits(bytes0)) + fillsgn(8, int2bits(b2i(by)))))) ' = bytes0 + by ' |
⊦ n = # bits → lastn(n, bits0 + bits) = bits
8 ≠ # fillsgn(8, int2bits(b2i(by))), b2i(bytes0.first) = ~1, 0 ≤ b2i((bytes0.rest + by ').first), false ∈ bytes2bits(bytes0), true ∈ bytes2bits(bytes0), ∀ bytes1. # bytes1 < #(bytes0 + by ') → b2i(bytes1.first) = ~1 ∧ 0 ≤ b2i(bytes1.rest.first) → bits2bytes(sgn(bytes2bits(bytes1))) = bytes1 ∨ # bytes1 = 1 ∨ bytes1 = [] ⊦ bytes0 = [], bits2bytes(sgn(bytes2bits(bytes0))) + i2b(bits2int(lastn(8, sgn(bytes2bits(bytes0)) + fillsgn(8, int2bits(b2i(by)))))) ' = bytes0 + by '
8 = # fillsgn(8, int2bits(b2i(by))), b2i(bytes0.first) = ~1, 0 ≤ b2i((bytes0.rest + by ').first), false ∈ bytes2bits(bytes0), true ∈ bytes2bits(bytes0), ∀ bytes1. # bytes1 < #(bytes0 + by ') → b2i(bytes1.first) = ~1 ∧ 0 ≤ b2i(bytes1.rest.first) → bits2bytes(sgn(bytes2bits(bytes1))) = bytes1 ∨ # bytes1 = 1 ∨ bytes1 = [] ⊦ bytes0 = [], bits2bytes(sgn(bytes2bits(bytes0))) + i2b(bits2int(fillsgn(8, int2bits(b2i(by))))) ' = bytes0 + by '
Used terms: fillsgn(8, int2bits(b2i(by))), sgn(bytes2bits(bytes0)), 8