-- -*- M2-comint -*- {* hash: 1900774526 *}

i1 : R = QQ[a..e];

i2 : G = graph {a*b,a*c,a*d,d*e}

o2 = Graph{edges => {{a, b}, {a, c}, {a, d}, {d, e}}}
           ring => R
           vertices => {a, b, c, d, e}

o2 : Graph

i3 : lineGraph G

o3 = Graph{edges => {{x , x }, {x , x }, {x , x }, {x , x }}}
                       0   1     0   2     1   2     2   3
           ring => QQ[x , x , x , x ]
                       0   1   2   3
           vertices => {x , x , x , x }
                         0   1   2   3

o3 : Graph

i4 :