 Stevenson does not permit combinations of sortal expressions, presumably because there is no easy way to deal with disjunctions and conjunctions of sortals in his formulation. However, a slight complication of his language would suffice to handle the problem. He uses “uS” for the ultimate sortal which governs sortal “S”. If instead he introduced a set of letters \(U'\), \(U''\) … for ultimate sortals, he could then superscript sortal expressions to indicate the ultimate sortal that governs them. He could then permit the disjunction of \(S^{U'}\) and \(T^{U'}\) since they are governed by the same ultimate sortal, but forbid the disjunction of \(S^{U'}\) and \(T^{U'}\) since they are governed by different ultimate sortals.