  The first-order logical environment FOLE [5] provides a rigorous and
principled approach to distributed interoperable first-order information
systems. FOLE has been developed in two forms: a classification form and an
interpretation form. Two papers represent FOLE in a classification form
corresponding to ideas of the Information Flow Framework [11],[12],[13]: the
first paper [6] provides a foundation that connects elements of the ERA data
model [2] with components of the first-order logical environment FOLE; the
second paper [7] provides a superstructure that extends FOLE to the formalisms
of first-order logic. The formalisms in the classification form of FOLE provide
an appropriate framework for developing the relational calculus. Two other
papers represent FOLE in an interpretation form: the first paper [8] develops
the notion of the FOLE table following the relational model [3]; the second
paper [9] discusses the notion of a FOLE relational database. All the
operations of the relational algebra have been rigorously developed [10] using
the interpretation form of FOLE. The present study demonstrates that the
classification form of FOLE is informationally equivalent to the interpretation
form of FOLE. In general, the FOLE representation uses a conceptual structures
approach, that is completely compatible with formal concept analysis [4] and
information flow [1].
