 Collective compositionality is a further weakening of global compositionality. It could be formalized using the same trick. Thus, we can say that m is collectively compositional just in case collectively equivalent pairs of expressions are all synonyms, where we define collective equivalence exactly like global equivalence with one difference. In the recursive step we demand not only that \(e_i\) and \(e_i '\) be j-collective equivalents but also that the very same semantic relations should hold among \(e_1 ,\ldots ,e_k\) and among \(e_1 ',\ldots ,e_k '\). Thus, we leave space for the possibility that ‘Cicero is Cicero’ is not collectively equivalent to ‘Cicero is Tully’, even though they have the same structure and their proper constituents are all collectively equivalent; see  section 1.4.  