The Bactra Review Emergence

Let us lapse into mathematical logic ---
Holland doesn't, but I doubt these parts of his book can be followed
*easily* by anyone who can't make the silent mental adjustments into
notation. We have a relation R among a class of terms A, and we write R(a, b)
if the relation holds between a and b. (This is of a piece with the usual
definition of a relation as a class of ordered pairs. Note that R(a, b) is not
the same as R(b, a), unless a=b.) We can model R by another relation Q,
between a different class of terms M, if there is an invertible function S from
A to M such that R(a,b) iff Q(S(a), S(b)); as Russell would say, R and Q have
the same relation-number. (This is easily extended to non-binary relations.)
A model for Holland is thus essentially the same as a "representation" for
Russell in "Vagueness," and rather like
an "interpretation" for Sperber and Wilson in Relevance. Holland
is primarily concerned with models of processes, where the relevant relation is
causation, or, if you prefer, succession.