(a.) See FitchE.

Doppelganger actual thing apograph carbon copy dead ringer ditto double duplicate equivalent exact counterpart facsimile fiche homograph homonym homophone idem identical same manifold microcopy microfiche microform no other none other recording reduplication replica replication rubbing selfsame spit and image spitting image synonym tenor the same the same difference tracing transcript transcription transfer twin very image very same