| 1 < # bits ∧ 1 < #(false ' + bits0), ∀ bits1, bits0. # bits1 < # bits → true → bits1 = [] ∨ bitsand(bits1, false ' + bits0) = false ' + bits0 ∨ false ∈ bits1 ∨ false ∈ bits0 ⊦ bitsand(bits.butlast, (false ' + bits0).butlast) + (bits.last ∧ (false ' + bits0).last) = false ' + bits0, bits = [], false ∈ bits0, false ∈ bits |
∀ bits1, bits0. # bits1 < # bits → true → bits1 = [] ∨ bitsand(bits1, false ' + bits0) = false ' + bits0 ∨ false ∈ bits1 ∨ false ∈ bits0 ⊦ bits = bits.first ', bits0 = [], bits = [], bitsand(bits.butlast, false ' + bits0.butlast) + (bits0.last ∧ bits.last)' = false ' + bits0, false ∈ bits0, false ∈ bits
Used simplifier rules: ⊦ bits ≠ [] → ((boolvar ' + bits).last ↔ bits.last);% ⊦ bits ≠ [] → (bits0 + bits).butlast = bits0 + bits.butlast;% ⊦ m + n = 1 ↔ m = 0 ∧ n = 1 ∨ n = 0 ∧ m = 1;% ⊦ m + n = n + m;% ⊦ (m + n0) + n1 = m + n0 + n1;% ⊦ m + 1 ≠ 0;% ⊦ # boolvar ' = 0 +1;% ⊦ #(bits + bits0) = # bits + # bits0;% ⊦ (bits + bits0) + bits1 = bits + bits0 + bits1;% ⊦ bits + [] = bits;% ⊦ boolvar + bits = boolvar ' + bits;% ⊦ # bits = 1 ↔ bits = bits.first + [];% ⊦ # bits = 0 ↔ bits = [];% ⊦ 1 < m ↔ ¬(m = 0 ∨ m = 1);% ⊦ bits + boolvar = bits + boolvar ';