A copy on Beta https://en.wikipedia.beta.wmflabs.org/wiki/Extension:Math/Torture_Test

Recreating the MathML torture test old version 20+ years old, new version from 2021 that allows different font's to be used.

Rendering of TortureTest

Number	LaTex	MathML	Notes
1	x^2y^2 || ${\displaystyle x^{2}y^{2}}$
2	{ }_2F_3 || ${\displaystyle {}_{2}F_{3}}$
3	\frac{x+y^2}{k+1} || ${\displaystyle {\frac {x+y^{2}}{k+1}}}$
3b	{x+y^2 \over k + 1} || ${\displaystyle {x+y^{2} \over k+1}}$
4	x + y^{\frac{2}{k+1} } || ${\displaystyle x+y^{\frac {2}{k+1}}}$
5	\frac{a}{b/2} || ${\displaystyle {\frac {a}{b/2}}}$	T375337
6	a_0 + \frac{1}{\displaystyle a_1 + \frac{1}{\displaystyle a_2 + \frac{1}{\displaystyle a_3 + \frac{1}{a_4} } } } || ${\displaystyle a_{0}+{\frac {1}{\displaystyle a_{1}+{\frac {1}{\displaystyle a_{2}+{\frac {1}{\displaystyle a_{3}+{\frac {1}{a_{4}}}}}}}}}}$
7	a_0 + \tfrac{1}{a_1+\tfrac{1}{a_2+\tfrac{1}{a_3+\tfrac{1}{4} } } } || ${\displaystyle a_{0}+{\tfrac {1}{a_{1}+{\tfrac {1}{a_{2}+{\tfrac {1}{a_{3}+{\tfrac {1}{4}}}}}}}}}$
8	\binom{n}{k/2} || ${\displaystyle {\binom {n}{k/2}}}$
9	\binom{p}{2}x^2y^{p-2}-\frac{1}{1-x}\frac{1}{1-x^2} || ${\displaystyle {\binom {p}{2}}x^{2}y^{p-2}-{\frac {1}{1-x}}{\frac {1}{1-x^{2}}}}$
10a	\sum_\substack{0 \le i \le m \\ 0 < j < n} P(i,j) }}		Not currently supported T318784. See
10b	\sum_{{}^{0 \le i \le m}_{0 < j < n}} P(i,j) || ${\displaystyle \sum _{{}_{0<j<n}^{0\leq i\leq m}}P(i,j)}$
11	x^{2y} || ${\displaystyle x^{2y}}$
12	x^2 || ${\displaystyle x^{2}}$
13	\sqrt{1+\sqrt{1+\sqrt{1+\sqrt{1+\sqrt{1+\sqrt{1+\sqrt{1+x} } } } } } } || ${\displaystyle {\sqrt {1+{\sqrt {1+{\sqrt {1+{\sqrt {1+{\sqrt {1+{\sqrt {1+{\sqrt {1+x}}}}}}}}}}}}}}}$
14	\left( \frac{\partial}{\partial x^2}+\frac{\partial}{\partial x^2} \right) \left|\varphi(x+i y)\right|^2 = 0 || ${\displaystyle \left({\frac {\partial }{\partial x^{2}}}+{\frac {\partial }{\partial x^{2}}}\right)\left|\varphi (x+iy)\right|^{2}=0}$
15	2^{2^{2^x} } || ${\displaystyle 2^{2^{2^{x}}}}$
16	\int_1^x \frac{dt}{t} || ${\displaystyle \int _{1}^{x}{\frac {dt}{t}}}$
17	\iint_D dx dy || ${\displaystyle \iint _{D}dxdy}$
18	f(x) = \begin{cases} 1/3 & \text{if } 0 \le x \le 1 \\ 2/3 & \text{if } 3 \le x \le 4 \\ 0 & \text{elsewhere} \end{cases} || ${\displaystyle f(x)={\begin{cases}1/3&{\text{if }}0\leq x\leq 1\\2/3&{\text{if }}3\leq x\leq 4\\0&{\text{elsewhere}}\end{cases}}}$
19	\overbrace{ x+\cdots+x }^{k\text{ times} } || ${\displaystyle \overbrace {x+\cdots +x} ^{k{\text{ times}}}}$
20	y_{x^2} || ${\displaystyle y_{x^{2}}}$
21	\sum_{p\text{ prime} } f(p) = \int_{t>1} f(t) d\pi(t) || ${\displaystyle \sum _{p{\text{ prime}}}f(p)=\int _{t>1}f(t)d\pi (t)}$
22	\underbrace{ \overbrace{a,\ldots,a}^{k\,a\text{'s} }, \overbrace{b,\ldots,b}^{l\ b\text{'s} } }_{k+l\text{ elements} } || ${\displaystyle \underbrace {\overbrace {a,\ldots ,a} ^{k\,a{\text{'s}}},\overbrace {b,\ldots ,b} ^{l\ b{\text{'s}}}} _{k+l{\text{ elements}}}}$
23	\begin{pmatrix} \begin{pmatrix}a&b\\c&d\end{pmatrix} & \begin{pmatrix}e&f\\g&h\end{pmatrix} \\ 0 & \begin{pmatrix}i&j\\k&l\end{pmatrix} \end{pmatrix} || ${\displaystyle {\begin{pmatrix}{\begin{pmatrix}a&b\\c&d\end{pmatrix}}&{\begin{pmatrix}e&f\\g&h\end{pmatrix}}\\0&{\begin{pmatrix}i&j\\k&l\end{pmatrix}}\end{pmatrix}}}$	T375346 Lots of space around the cells in matrix evironments in MathML mode
24	\det\begin{vmatrix} c_0 & c_1 & c_2 & \ldots & c_n \\ c_1 & c_2 & c_3 & \ldots & c_{n+1} \\ c_2 & c_3 & c_4 & \ldots & c_{n+2} \\ \vdots & \vdots & \vdots & & \vdots \\ c_n & c_{n+1} & c_{n+2} & \ldots & c_{2n} \end{vmatrix}>0 || ${\displaystyle \det {\begin{vmatrix}c_{0}&c_{1}&c_{2}&\ldots &c_{n}\\c_{1}&c_{2}&c_{3}&\ldots &c_{n+1}\\c_{2}&c_{3}&c_{4}&\ldots &c_{n+2}\\\vdots &\vdots &\vdots &&\vdots \\c_{n}&c_{n+1}&c_{n+2}&\ldots &c_{2n}\end{vmatrix}}>0}$
25	y_{x_2} || ${\displaystyle y_{x_{2}}}$
26	x^{31415}_{92} || ${\displaystyle x_{92}^{31415}}$
27	x^{z^d_c}_{y^a_b} || ${\displaystyle x_{y_{b}^{a}}^{z_{c}^{d}}}$
28	y^{\prime\prime\prime}_3 || ${\displaystyle y_{3}^{\prime \prime \prime }}$