def head_link
import bend-prot@0.1.0.0/topology.bend as Topologyimport Base
import bend-prot@0.1.0.0/protein.bend as P
133def head_link(h: P.Atom, +ys: List<&2, P.Atom>) -> Maybe<&2, F32>:
134 match h:
135 case P.Atom{serial, elem, +pos}:
136 min_dist2_to(ys, pos)