| 1 < # bits ∧ 1 < # bits0, ∀ bits, bits1. # bits1 < # bits0 → true → bits ≠ [] ∧ bits1 ≠ [] → bitsor(bits, bits1) = bitsor(bits1, bits) ⊦ bits = [], bits0 = [], bitsor(bits.butlast, bits0.butlast) + (bits.last ∨ bits0.last) = bitsor(bits0, bits) |
∀ bits, bits1. # bits1 < # bits0 → true → bits ≠ [] ∧ bits1 ≠ [] → bitsor(bits, bits1) = bitsor(bits1, bits) ⊦ bits = [], bits0 = [], bitsor(bits.butlast, bits0.butlast) + (bits.last ∨ bits0.last)' = bitsor(bits0, bits), # bits = 1, # bits0 = 1
Used simplifier rules: ⊦ # bits = 0 ↔ bits = [];% ⊦ 1 < m ↔ ¬(m = 0 ∨ m = 1);% ⊦ bits + boolvar = bits + boolvar ';