Categories Everywhere?

• \(\Mon\): (monoids, monoid morphisms,∘)
• \(\Vec\): (Vectorial spaces, linear functions,∘)
• \(\Grp\): (groups, group morphisms,∘)
• \(\Rng\): (rings, ring morphisms,∘)
• Any deductive system T: (theorems, proofs, proof concatenation)
• \( \Hask\): (Haskell types, functions, (.) )
• ...