permutability
/pəˌmjuːtəˈbɪlɪti/noun
The quality or condition of being permutable; interchangeability; (Mathematics and Logic ) the property of having elements that can be interchanged without affecting the validity of a statement.
Origin
Mid 17th century (in an earlier sense). In sense 1 from post-classical Latin permutabilitas from permutabilis + classical Latin -tās.