| # bits0 = # bits2, ∀ bits1, bits, bits2, bits3. # bits3 < # bits0 → true → # bits3 = # bits2 ∧ bits ≠ [] ∧ bits3 ≠ [] ∧ bits1 ≠ [] ∧ bits2 ≠ [] → bitsor(bits + bits3, bits1 + bits2) = bitsor(bits, bits1) + bitsor(bits3, bits2) ⊦ bits = [], bits0 = [], bits1 = [], bits2 = [], bitsor(bits + bits0, bits1 + bits2) = bitsor(bits, bits1) + bitsor(bits0, bits2) |
⊦ 1 < # bits ∧ 1 < # bits0 → bitsor(bits, bits0) = bitsor(bits.butlast, bits0.butlast) + (bits.last ∨ bits0.last)
1 < #(bits + bits0) ∧ 1 < #(bits1 + bits2), # bits0 = # bits2, ∀ bits1, bits, bits2, bits3. # bits3 < # bits0 → true → # bits3 = # bits2 ∧ bits ≠ [] ∧ bits3 ≠ [] ∧ bits1 ≠ [] ∧ bits2 ≠ [] → bitsor(bits + bits3, bits1 + bits2) = bitsor(bits, bits1) + bitsor(bits3, bits2) ⊦ bits = [], bits0 = [], bits1 = [], bits2 = [], bitsor((bits + bits0).butlast, (bits1 + bits2).butlast) + ((bits + bits0).last ∨ (bits1 + bits2).last) = bitsor(bits, bits1) + bitsor(bits0, bits2)
Used simplifier rules: ⊦ #(bits + bits0) = # bits + # bits0;% ⊦ (bits + bits0) + bits1 = bits + bits0 + bits1;% ⊦ 1 < m ↔ ¬(m = 0 ∨ m = 1);% ⊦ m + n = 0 ↔ m = 0 ∧ n = 0;% ⊦ # bits = 0 ↔ bits = [];% ⊦ (m + n0) + n1 = m + n0 + n1;% ⊦ m + n = n + m;% ⊦ # bits + # bits0 = 1 ∧ bits ≠ [] → # bits = 1 ∧ bits0 = []; (forward) Used terms: bits1 + bits2, bits + bits0