is_normal

property Subset.is_normal

Return True if the subset is normal (invariant under conjugation).

A subset, \(N\), is called normal if it is invariant under conjugation by elements of the head group, \(G\). This means for every element \(g\) in \(G\) and every element \(n\) in \(N\), the element \(g*n*g^{-1}\) is an element in \(N\).