, have some form of internal contact with the boundary of
. The closest form of such contact is to be injoined in
. But there will also be more abstract types of point-contact or of line-contact which we have not defined here, but know about from their occurrence in geometry. If we merely exclude such cases without explicit definition, we are really appealing to fundamental relations and properties which have not been explicitly recognised. We must use definitions based solely upon those properties of the relation
which have been made explicit. We cannot explicitly take account of point-contact till points have been defined.
[32. Abstractive Elements]. 32.1 A 'finite abstractive element deduced from the formative condition
