Group action on a tree
= Group action on a tree
{wiki=Bass–Serre_theory}
A group action on a tree is a homomorphism to the tree's combinatorial isometry group. Barycentric subdivision removes edge inversions without changing the essential action.
= Group action on a tree
{wiki=Bass–Serre_theory}
A group action on a tree is a homomorphism to the tree's combinatorial isometry group. Barycentric subdivision removes edge inversions without changing the essential action.