Every proposition which says something indefinable about a thing is a
subject-predicate proposition; every proposition which says something
indefinable about two things expresses a dual relation between these
things, and so on.
Thus every proposition which contains only one name and one
indefinable form is a subject-predicate proposition, and so
on.
An
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indefinable simple symbol can
only be a name, and therefore we can know, by the symbol of an atomic
proposition, whether it is a subject-predicate proposition.