Re: [PATCH 6/8] commit: provide a fast multi-tip contains function

> What does it mean to look for "branch --with $commit1 $commit2"
> (i.e. more than one in the Left set)?  If we are trying to see which
> branches reach _both_ of these commits, then replace the ablve with
> "if a commit is already painted as reachable from both $commit{1,2},
> then painting it with any branch bits is futile---its parents will
> never reach either $commit1 nor $commit2", so the additional
> termination condition will be "If left bits are full, then stop".
>
> I do not know how you can optimize the traversal if you are trying
> to see which branches reach at least one of these commits, though.