  Braids can be represented geometrically as laminations of punctured disks.
The geometric complexity of a braid is the minimal complexity of a lamination
that represents it, and tight laminations are representatives of minimal
complexity. These laminations give rise to a normal form of braids, via a
relaxation algorithm. We study here this relaxation algorithm and the
associated normal form. We prove that this normal form is regular and
prefix-closed. We provide an effective construction of a deterministic
automaton that recognizes this normal form.
