(17) "Elsewhere Condition" Pref(v,w) is not defined in case for some v' such that πc(v') is a subcategory of πc(v) - and furthermore, v' and v have the same semantic projection - Pref(v',w) is defined. Similarly, Suff(v,w) is not defined if for some w' such that πc(w') is a subcategory of πc(w) and πs(w') = πs(w), Pref(v,w') is defined. - Hoeksma (2004), a pag.204