| ∀ bits2, bits0, bits1. # bits2 < # bits → true → bits2 = [] ∨ bits0 = [] ∨ bits1 = [] ∨ bitsand(bits2, bitsand(bits0, bits1)) = bitsand(bitsand(bits2, bits0), bits1) ⊦ bitsand(bits, bitsand(bits0, bits1)) = bitsand(bitsand(bits, bits0), bits1), bits1 = [], bits0 = [], bits = [] |
⊦ 1 < # bits ∧ 1 < # bits0 → bitsand(bits, bits0) = bitsand(bits.butlast, bits0.butlast) + (bits.last ∧ bits0.last)
¬(1 < # bits0 ∧ 1 < # bits1), ∀ bits2, bits0, bits1. # bits2 < # bits → true → bits2 = [] ∨ bits0 = [] ∨ bits1 = [] ∨ bitsand(bits2, bitsand(bits0, bits1)) = bitsand(bitsand(bits2, bits0), bits1) ⊦ bitsand(bits, bitsand(bits0, bits1)) = bitsand(bitsand(bits, bits0), bits1), bits1 = [], bits0 = [], bits = []
1 < # bits0 ∧ 1 < # bits1, ∀ bits2, bits0, bits1. # bits2 < # bits → true → bits2 = [] ∨ bits0 = [] ∨ bits1 = [] ∨ bitsand(bits2, bitsand(bits0, bits1)) = bitsand(bitsand(bits2, bits0), bits1) ⊦ bitsand(bits, bitsand(bits0.butlast, bits1.butlast) + (bits0.last ∧ bits1.last)) = bitsand(bitsand(bits, bits0), bits1), bits1 = [], bits0 = [], bits = []
Used terms: bits1, bits0