Propositions say something about the world. In this video we define
the meanings of some Aristotelian propositions. The meaning is given
by defining the validity of a proposition in a universe. This
formal notion of validity represents the informal notion of truth.
Once you have listened to this video, you may want to listen to
the first part of this recording of a lecture delivered in 2019
Up to 7m20s this is another presentation of the materials covered in
this and the preceding videos. Beyond that it goes into the Haskell
representation of our small universe (see below).