| bitsand(bits, bits0) = [] ⊦ bits = [], bits0 = [], bits0 = true ', bits0 = false ', bits = true ', bits ≠ bits.first ' ∧ bits0 ≠ bits0.first ' |
⊦ bits0 ≠ [] ∧ bits = false ' → bitsand(bits, bits0) = false '
¬(bits0 ≠ [] ∧ bits = false '), bitsand(bits, bits0) = [] ⊦ bits = [], bits0 = [], bits0 = true ', bits0 = false ', bits = true ', bits ≠ bits.first ' ∧ bits0 ≠ bits0.first '
Used terms: bits0, bits