typedef typename tree_match<iterator_t, NodeFactoryT, T>::container_t
container_t;
- // test for size() is nessecary, because no_tree_gen_node leaves a.trees
+ // test for size() is necessary, because no_tree_gen_node leaves a.trees
// and/or b.trees empty
if (0 != b.trees.size() && b.trees.begin()->value.is_root())
{