| ∀ n, bits, bits1. # bits1 < # bits0 → true → bits = [] ∨ bits1 = [] ∨ fillsgn(n, bitsand(fillsgn(n, bits), bits1)) = fillsgn(n, bitsand(bits, bits1)) ⊦ bits0 = [], fillsgn(n, bitsand(mklist(false, n), bits0)) = mklist(false, n), n = 0 |
⊦ ¬ true ∈ bits ∧ (# bits0 < # bits ∧ ¬ bits0.first) ∧ bits ≠ [] ∧ bits0 ≠ [] → bitsand(bits, bits0) = mklist(false, # bits0)
¬(¬ true ∈ mklist(false, n) ∧ # bits0 < # mklist(false, n) ∧ ¬ bits0.first ∧ mklist(false, n) ≠ [] ∧ bits0 ≠ []), ∀ n, bits, bits1. # bits1 < # bits0 → true → bits = [] ∨ bits1 = [] ∨ fillsgn(n, bitsand(fillsgn(n, bits), bits1)) = fillsgn(n, bitsand(bits, bits1)) ⊦ bits0 = [], fillsgn(n, bitsand(mklist(false, n), bits0)) = mklist(false, n), n = 0
¬ true ∈ mklist(false, n) ∧ # bits0 < # mklist(false, n) ∧ ¬ bits0.first ∧ mklist(false, n) ≠ [] ∧ bits0 ≠ [], ∀ n, bits, bits1. # bits1 < # bits0 → true → bits = [] ∨ bits1 = [] ∨ fillsgn(n, bitsand(fillsgn(n, bits), bits1)) = fillsgn(n, bitsand(bits, bits1)) ⊦ bits0 = [], fillsgn(n, mklist(false, # bits0)) = mklist(false, n), n = 0
Used terms: bits0, mklist(false, n)