i1 : R = QQ[a,b,c,d,MonomialOrder=>Lex];

i2 : DG = digraph {{"a0","b0"}, {"a0","b1"}, {"a1","b2"}, {"b0","c1"}, {"b1","c0"}, {"b2","c0"}, {"c0","d0"}, {"c1","d1"}}
o2 = Digraph{a0 => {b0, b1}}
a1 => {b2}
b0 => {c1}
b1 => {c0}
b2 => {c0}
c0 => {d0}
c1 => {d1}
d0 => {}
d1 => {}
o2 : Digraph

i3 : G = chordalGraph digraph hashTable{a=>{b,c},b=>{c},c=>{d},d=>{}};

i4 : tree = elimTree G
o4 = ElimTree{a => c}
b => c
c => d
d => b
o4 : ElimTree

i5 : rnk = hashTable{"a0"=>a, "a1"=>a, "b0"=>b, "b1"=>b, "b2"=>b,
"c0"=>c, "d0"=>d, "c1"=>c, "d1"=>d};

i6 : eqs = hashTable{"a0" => ({a},{}), "a1" => ({},{}),
"b0" => ({b},{}), "b1" => ({},{}), "b2" => ({b},{}),
"c0" => ({c},{}), "c1" => ({},{}),
"d0" => ({},{}), "d1" => ({d},{}) };

i7 : chordalNet(eqs,rnk,tree,DG)
o7 = ChordalNet{ a => {a, } }
c => { , c}
d => { , d}
b => {b, , b}
o7 : ChordalNet
