[SCL] Is the notion of predicate position abstract or abstractable?

[Robert E. Kent]

> The term 'predicate position' was used only in informal emails within
> the group, but it has a fairly crisp definition. It refers to a
> component of the abstract syntax, to wit, the relational term which
> is the head of an atomic sentence.

The term 'predicate position' is used at least five times in the SCL
document "Abstract Syntax and Semantics for SCL". And I understand that it
refers to the the head of an atomic sentence, or more abstractly to the
element of Predn or Predω in the expression
     ∪n∈N{Predn  × Tn} ∪ (Predω × (Tω ∪ (Tω × SeqVar))).
But the symmetric relation example was given in the SCL document as an
example of the use of quantified variables occuring in predicate position.
My example aimed to indicate an abstraction which eliminated the notion of
"predicate position". What I would like to see is an example where
quantifying over predicate position is absolutely necessary, and cannot be
abstracted away. But I think my abstraction is different from the abstract
syntax as presented in the SCL document, and thus will not be acceptable to
SUO folk.

Robert E. Kent
rekent at ontologos.org