ASCII math notation

Internet shorthand notation is a notation widely used on Internet sites, where typing mathematical expressions is too complicated for practicality. It is also used because of the inability to place variables and expressions in the standard positions. The most common way of such abbreviation is by using an in-line binary operator (+,-,*,\,...) as well as using parenthesis ( ) to correctly express quantities. Some examples are given below for commonly abbreviated expressions.

Exponentials

Standard:

$e^{x}\,$

Shorthand:

e^x,

or,

exp(x)

Limits

Standard:

$\lim _{x\to a}f(x)$

Shorthand:

lim(f(x),x,a),

or, in some cases,

lim_x->a f(x),

where a can be a finite quantity, or positive or negative infinity. The limit from the left may be called llim, and the limit from the right rlim. A right or left-sided limit could also be explained in nearby text. Otherwise, any of the following may denote a one-sided limit:

lim(f(x),x,a+)

lim(f(x),x,a-)

lim_x->a+ f(x)

lim_x->a- f(x)

Sums

Standard:

$\sum _{n=a}^{b}a_{n}$

Shorthand:

sum(a_n,n,a,b)

Integrals

Standard:

$\int _{a}^{b}f\left(x\right)dx$

Shorthand:

int(f(x),x,a,b)

Derivatives (in Leibniz notation)

Standard: ${\frac {df(x)}{dx}}$

Shorthand:

df(x)/dx

Partial derivatives

Standard:

${\frac {\partial f(x_{1},x_{2},\dots )}{\partial x_{n}}}$

Shorthand:

df(x_1,x_2,...)/dx_n,

or,

df(x1,x2,...)/dxn