+ if (dep_included_in($dep, $cand)) {
+ $prune->($cand);
+ return;
+ }
+ my @parents_with =
+ grep { dep_included_in($dep, $_) } @parents;
+ return if !@parents_with; # irrelevant merge
+ return if $pruned->($cand); # not interesting any more
+ $prune->($_) foreach @parents_with;
+
+
+ PROBLEM @prune is bad we want to know why
+ we have found thing not just whether found
+
+ #