  The IFF approach for the notion of "lattice of theories" uses the idea of a
concept lattice from Formal Concept Analysis (Ganter and Wille) and the idea of
the truth classification from Information Flow (Barwise and Seligman). The IFF
approach is concentrated in the joining of these two important ideas. The
result is called the truth concept lattice, the concept lattice of the truth
classification. The IFF provides a principled (versus ad hoc) approach for John
Sowa's "lattice of theories" framework. The "lattice of theories" is
represented by the truth concept lattice, each theory in the lattice is
represented by a formal concept in the truth concept lattice.
