**Conjecture**Suppose that is a -edge-critical graph. Suppose that for each edge of , there is a list of colors. Then is -edge-colorable unless all lists are equal to each other.

(Reproduced from [M].)

A graph is said to be -edge-critical if it is not -edge-colorable but every edge-deleted subgraph is -edge-colorable. (Here is the maximum degree of .)

## Bibliography

*[M] B. Mohar, Problem of the Month

* indicates original appearance(s) of problem.