Interesting names for mathematical symbols came up in conversation over coffee. I recalled a symbol that was commonly called "washing machine", looks like:
$\begin{bmatrix}0 & & &\\ \\ &&\Huge\circ && &\\\\ \\\end{bmatrix}$
(matrix brackets, zero upper left, large zero/circle in middle (I recall center circle as much larger, but could not get that rendered in LaTex).
A half hour of Google searching for "washing machine" & "mathematical symbol" and the such leads to nonsense.
IIRC, it had to do with linear algebra perhaps.
Here's hoping someone recognizes it.
Thanks.
It's a zero matrix. The central big zero is for all elements but the top left one. The top left zero is more generally nonzero. The name comes from it looking like a front-loading clothes washer. https://en.wikipedia.org/wiki/List_of_mathematical_jargon#Descriptive_informalities