A
graph G is supereulerian if it has a spanning eulerian sub
graph. We prove that every 3-edge-connected
graph with the circumference at most 11 has a spanning eulerian sub
graph if and only if it is not contractible to the
Petersen graph. As applications, we determine collections
F1,
F2 and
F3 of
graphs to prove each of the following
(i) Every 3-connected {K1,3,Z9}-free graph is hamiltonian if and only if its closure is not a line graph L(G) for some G∈F1.
(ii) Every 3-connected {K1,3,P12}-free graph is hamiltonian if and only if its closure is not a line graph L(G) for some G∈F2.
(iii) Every 3-connected {K1,3,P13}-free graph is hamiltonian if and only if its closure is not a line graph L(G) for some G∈F3.