is mentioned by

Def dfs(the_obj;s;i) == if member-paren(x,y.the_obj.eq(x,y);i;s) s else [inl(i) / (the_obj.eacc((s',j. dfs(the_obj;s';j)),[inr(i) / s],i))] fi (recursive)

[dfs]

In prior sections: prog 1 list 1 mb basic mb nat mb list 1 num thy 1 graph 1 1 graph 1 2

Try larger context: Graphs