For the purposes of this discussion, let us define an ''intentional proposition'' as a proposition in the universe of discourse Q''X''<sup> •</sup> = [Q<font face="lucida calligraphy">X</font>], in other words, a map ''q'' : Q''X'' → '''B'''. The sense of this definition may be seen if we consider the following facts. First, the equivalence Q''X'' = ''X'' × ''X''′ motivates the following chain of isomorphisms between spaces: | For the purposes of this discussion, let us define an ''intentional proposition'' as a proposition in the universe of discourse Q''X''<sup> •</sup> = [Q<font face="lucida calligraphy">X</font>], in other words, a map ''q'' : Q''X'' → '''B'''. The sense of this definition may be seen if we consider the following facts. First, the equivalence Q''X'' = ''X'' × ''X''′ motivates the following chain of isomorphisms between spaces: |