> > I will reiterate my suggestion to use finite sets for indexing when > possible, which sidesteps the question
Whatever the final decision on indexing start will be, I really hope that there still will be support for matrices indexed by arbitrary finite sets. I'm not sure if this example was mentioned before, but, for example, adjacency matrix of a graph can be indexed by graph vertices. It is often cumbersome to induce an arbitrary ordering on the vertices, and needless to say that many theorems do not require any ordering whatsoever (for instance, theorems about eigenvalues of subgraphs/submatrices). -- You received this message because you are subscribed to the Google Groups "Metamath" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/metamath/0e0d6497-1a3f-4590-b3ba-c53b2f66c141o%40googlegroups.com.
