 The first and most obvious problem is the same as with the similarity view: isomorphism is symmetrical and reflexive (and transitive) but representation isn’t. This problem could be addressed by replacing isomorphism with an alternative mapping. Bartels (2006), Lloyd (1984), and Mundy (1986) suggest homomorphism; van Fraassen (1980, 1997, 2008) and Redhead (2001) isomorphic embeddings; advocates of the partial structures approach prefer partial isomophisms (Bueno 1997; Bueno and French 2011; Da Costa and French 1990, 2003; French 2003, 2014; French and Ladyman 1999); and Swoyer (1991) introduces what he calls \(\Delta/\Psi\) morphisms. We refer to these collectively as “morphisms”. Pero and Suárez (2016) provide a comparative discussion of different morphisms.