| ¬(bits ≠ [] ∧ bits0 = true '), ∀ bits, bits1. # bits1 < # bits0 → true → bits ≠ [] ∧ bits1 ≠ [] → bitsor(bits, bits1) = bitsor(bits1, bits) ⊦ bits = [], bits0 = [], bitsor(bits, bits0) = bitsor(bits0, bits), # bits ≠ 1 ∧ # bits0 ≠ 1 |
∀ bits, bits1. # bits1 < # bits0 → true → bits ≠ [] ∧ bits1 ≠ [] → bitsor(bits, bits1) = bitsor(bits1, bits) ⊦ bits = [], bits0 = [], bitsor(bits, bits0) = bitsor(bits0, bits), bits0 = true ', # bits ≠ 1 ∧ # bits0 ≠ 1