This is a quick post about the Chinese Remainder Theorem. Specifically, how to use it to solve a system of system of simple modular equations.

One cool thing about lists is that they have canonical ways of consuming and producing them: folds, and unfolds. It turns out that these are canonical, in that folding and unfolding functions are themselves isomorphic to lists. In this post, we’ll explore why this is true.

The usual definition of a Group excludes empty groups by definition. There are alternate definitions of a Group that allow us to include the empty set, and which are quivalent to the normal definition in all other cases. This post explores this alternate definition, and the resulting differences with the normal concept of a Group. What is a Group? A Group is one of the most important structures in abstract algebra.