LaTeX considered evil
text{Here you can write text}
x in bb{R}
#ff0000{Red} is red{Red}
Sigma, sigma, pi, Pi
{1 f(x)} / {2 + 3}
sin x, cos x, tan x
matrix{
A B
C D
}
e^{x^2}
a_{ij}
sqrt{2}
{delta x} / {delta y}
lim {x->0} {2x^2 + 3x + 7}
sum {x = 0 to infinity} {x^2}