t I will focus mainly on logical applications, and
and so the TEC's I talk about will almost always have
the character of &quot;logical equivalence classes&quot; (LEC's).

An example that will figure heavily in the sequel
is given by rooted trees as the species of graphs
and a pair of equational transformation rules that
derive from the graphical calculi of C.S. Peirce,
as revived and extended by George Spencer Brown.

Here are the fundamental transformation rules,
also referred to as the &quot;arithmetic a