context: If the URI representing a resolved inter-document reference has a fragment, the reference is to the element obtained by applying the fragment to the referred-to document starting with its root element.

Since SMLIF does not require that the model being exchanged is a valid SML model, a fragment may resolve to any of the following:
0 elements
1 element
>1 element

Existing text assumes only 1 element is possible.  Need to cover other cases.  Other cases cannot occur if the SMLIF document is also a valid SML model, but 3.2 explicitly says SMLIF does not require the interchange set to form a valid SML model.