Snippets (math and computing)

Things to use or delete. See Snippets.

Sturmian word

In mathematics, a Sturmian word (Sturmian sequence or billiard sequence), named after Jacques Charles François Sturm, is a certain kind of infinitely long sequence of characters. Such a sequence can be generated by considering a game of English billiards on a square table. The struck ball will successively hit the vertical and horizontal edges labelled 0 and 1 generating a sequence of letters. This sequence is a Sturmian word.

Bathtub curve

The bathtub curve is widely used in reliability engineering. It describes a particular form of the hazard function which comprises three parts:

• The first part is a decreasing failure rate, known as early failures.
• The second part is a constant failure rate, known as random failures.
• The third part is an increasing failure rate, known as wear-out failures.

The name is derived from the cross-sectional shape of a bathtub: steep sides and a flat bottom.

https://en.wikipedia.org/wiki/Bathtub_curve

Slack variable

Slack variable: In an optimization problem, a slack variable is a variable that is added to an inequality constraint to transform it into an equality. Introducing a slack variable replaces an inequality constraint with an equality constraint and a non-negativity constraint on the slack variable.

Impossible Puzzle

• https://en.wikipedia.org/wiki/Sum_and_Product_Puzzle

Sorting algorithms

• https://www.youtube.com/watch?v=kPRA0W1kECg

"The Talk" (quantum computing)

• https://www.smbc-comics.com/comic/the-talk-3