Down

Pass down arguments of sum, integral, etc. to the next line, which
can generate shorthand to present reusable segments. While writing long
step-by-step equations, only certain parts of a line change. down
leverages Typst's context (from version 0.11.0) to help relieve the
pressure of writing long and repetitive formulae.

Import the package:

#import "@preview/down:0.1.0": *

Usage

Create new contexts by using camel-case commands, such as
Limit(x, +0). Retrieve the contextual with cLimit.

• Limit(x, c) and cLimit:

$
Lim(x, +0) x ln(sin x)
  = cLim ln(sin x) / x^(-1)
  = cLim x / (sin x) cos x
  = 0
$

• Sum(index, lower, upper) and cSum:

$
Sum(n, 0, oo) 1 / sqrt(n + 1)
  = Sum(#none, 0, #none) 1 / sqrt(n)
  = cSum 1 / n^(1 / 2)
$

• Integral(lower, upper, f, dif: [x]), cIntegral(f) and
  cIntegrated(f):

$
Integral(0, pi / 3, sqrt(1 + tan^2 x))
  = cIntegral(1 / (cos x))
  = cIntegrated(ln (cos x / 2 + sin x / 2) / (cos x / 2 - sin x / 2))
  = ln (2 + sqrt(3))
$

Refer to ./sample.pdf for more complex application.