Closed aidevnn closed 2 years ago
The issue comes from an invalid automorphism composition order.
Now, $\textup{Hol}(\mathbf{C}_2 \times \mathbf{C}_2) \simeq \mathbf{S}_4$
The following code gives the correct result.
var V = Product.Generate(new Cn(2), new Cn(2));
var autV = Group.AutomorphismGroup(V);
DisplayGroup.AreIsomorphics(autV, new Symm(3));
var sdp = Group.SemiDirectProd(V, autV);
DisplayGroup.AreIsomorphics(sdp, new Symm(4));
will output
Aut[C2 x C2] IsIsomorphicTo Symm3 : True
(C2 x C2) x: (Aut[C2 x C2]) IsIsomorphicTo Symm4 : True
Symmetric 4 group is isomorphic to Holomorph group of C2 x C2.
But the following code will output an invalid result.
output