is mentioned by

Def adjl_to_adjm(l) == Case(l) Case mk_adjlist(n; out ) = > mk_adjmatrix(n, i,j. (kout(i).k=j))	[adjl_to_adjm]
Def adjm_to_adjl(m) == Case(m) Case mk_adjmatrix(n,f) = > mk_adjlist(n, i.filter(j.f(i,j);upto(0;n)))	[adjm_to_adjl]

In prior sections: mb basic

Try larger context: Graphs