digraph G { a_1 [texlbl="$\frac{\gamma}{2x^2+y^3}$"]; a_1 -> a_2 -> a_3 -> a_1 node [texmode="math"]; a_1 -> b_1 -> b_2 -> a_3; b_1 [label="\\frac{\\gamma}{x^2}"]; node [texmode="verbatim"] b_4 [label="\\beta"] a_3 -> b_4 -> a_1; }