| sgn(bits) = boolvar ' + boolvar ', boolvar ∈ sgn(bits) ⊦ |
∀ boolvar. ¬(sgn(bits0) = boolvar ' + boolvar ' ∧ boolvar ∈ sgn(bits0)) ⊦ ¬(sgn(boolvar + bits0) = boolvar0 ' + boolvar0 ' ∧ boolvar0 ∈ sgn(boolvar + bits0))
Used simplifier rules: sgn-empty: ⊦ sgn([]) = [];%bitlist freely generated by [], +;;% ⊦ ¬ bits + bits0 ≠ [] ↔ bits = [] ∧ bits0 = [];% ⊦ boolvar ' ≠ [];% ⊦ (bits + bits0) + bits1 = bits + bits0 + bits1;