Kwan adds, "The graph isomorphism problem does not seem hard, but we somehow can't yet prove that it's easy." Graphs are used ...

The problem is easy to state, but tricky to solve ... them to Merlin and asking him which was which. If the two graphs are really isomorphic, there’s no way Merlin could tell.

With such a setup it’s easy to make two initially ... all the balls share the same connections. Graphs that share this relationship are isomorphic. Computers generally have little trouble ...

A simple way to match two graphs is to check ... that find the symmetries of a graph — all the ways to generate isomorphic graphs by renaming nodes. At its heart is a new routine that can ...