x2.
x2xz.
x2 3^
x2 32
5
xz.
xxyz.
zz.
~/Library/MultiMarkdown
test
10
x^y
x~y
x2 3~
H2O
15
CH3CH2CH2CH3
CH3CH2CH2CH~3
\pi^2
\pi^2^
CH~4
20
CH~4~
238U
Ca2+
tpx
23Na1+
25
Na1+
Na^+
Na+