Testing tensor indices <mmultiscripts>: ${}_k{}^{3}R_i^1{}_j{}^2$; This with <none/>, ${}_{i}A_q^p$; A bit of calculus: ${\int }_a^{b}f\left(x\right)\mathrm{dx}\frac{\partial }{\partial x}F(x,y)+\frac{\partial }{\partial y}F(x,y)$; Here is the alphabet with invisible portions wrapped by <mphantom> in between: $abc\phantom{defghij}klmno\phantom{pqrs}tuvwxyz$. Testing MathML <msub>: $a_b$; $a_i$; $A_{I_k}$; Testing MathML <msup>: $d^b{2}^{a_x}{2^2}^x{\left(\frac{1}{2}\right)}^{y^{a_x}}$. Testing MathML <munder>, <mover>, and <munderover>: $\underset{\mathrm{un}}{\mathrm{abcd}}\stackrel{\mathrm{ov}}{\mathrm{abcd}}\underset{\mathrm{under}}{\overset{\mathrm{over}}{\mathrm{abcd}}}$. Testing MathML <msubsup>: $a_p^q{a}_{b+c}^x$. Testing MathML <mrow>: $d^{\left(\frac{a}{b}\right)}$; $x^2+4*x+\frac{p}{q}=0$, with this <mfrac> hanging here $\frac{d*T^{\left(\frac{i+j}{n}\right)}+p_y*q}{p^x*b_x+\frac{a+c}{d}}$ in the middle of a lot of running text to try to explain what this means to those who care to read. Testing MathML merror, mtext, $\text{This is a text in mtext}\text{This is a text in merror}$