"… every sufficiently good analogy is yearning to become a functor."
— John Baez, 2004: "Lessons from Topological Quantum Field Theory"
Related images — Quoting scripture at The Master's University
on Jan. 31, 2017 —
… and some images (re)posted here on that same date — Jan. 31, 2017:
A related analogy — Between (1) and (2) below —
-
A right triangle A as the sum of two smaller,
inner, right triangles B and C, each similar to A . -
The square on the longest side of A as the sum
of the squares on the longest sides of B and C.
Exercise for Baez fans: Express the above analogy as a functor.