hello g?ran,
there is not yet a way to select the tex flavor.
at present probably the best thing to do is just define the
stuff you want in a file (e.g. as posted by chris sangwin,
thanks chris) and load that.
i'd like to make it possible to select tex, latex, or amstex
for output, but i haven't come up with a good scheme for that.
what i'm thinking is that when latex or amstex is selected,
most tex properties default to plain tex, and the specialized
properties are used only if defined. i can imagine a way to
make that happen with the lisp property system, although
the stuff i've come up with seems clumsy. maybe someone
has some ideas here.
best,
robert dodier