Empty DTR Map same as no DTR Map?

Hi,

I recently struggled over a rare use-case I am not sure about.

EXI has Datatype Representation Maps[1] to specify alternate built-in EXI datatype representations or user-defined datatype representations for specific schema datatypes.

The use-case I encountered was as follows. The EXI options contains an
"datatypeRepresentationMap" element with no child elements.

According to my understanding, IF DTR maps are in use the representation of some types is different (e.g., unsignedInteger's are represented as integer etc)

With no child elements in "datatypeRepresentationMap" I wonder whether this use-case is as

a) no DTR map was defined OR

b) DTR maps are in use but with no alternate representation

Any thoughts?

Thanks,

-- Daniel

[1] https://www.w3.org/TR/exi/#datatypeRepresentationMap