ry specialized ones.  And once you prove that langauge A
can simulate a Turing machine, it is only necessary to show
that another language B can simulate A.

&gt;I would also argue that describing a modelling notation in terms of FOL is

&gt;only a part of the picture - the weakness of many notations, it seems to me,

&gt;is that the mapping between the model and the world is not sufficiently
&gt;defined (which I guess is often but not always an ontological problem).

Yes, the ontology is often the most imp