// Licensed under the Creative Commons Attribution-ShareAlike 4.0 International License.
// https://creativecommons.org/licenses/by-sa/4.0/

// Meta data
#set document(title: "Typst Math for Undergrads", author: "johanvx")

// Margin
#set page(margin: 0.5in)

// Font size
#let scriptsize = 7pt
#let normalsize = 10pt
#let large = 12pt
#set text(size: normalsize, lang: "en")

// Some horizontal spacing
#let kern(length) = h(length, weak: true)
#let enspace = kern(0.5em)
#let qquad = h(2em)

// For table/grid, something like "lhs \enspace rhs"
#let cell(lhs, rhs) = box(lhs + enspace + rhs)
// Grid for code blocks
#set grid(columns: (2em, auto))
// Table for math-code listing
#set table(stroke: none, align: horizon + left, inset: 0pt, row-gutter: 0.45em)

// LaTeX and TeX logos
#let TeX = style(styles => {
  let e = measure(text(normalsize, "E"), styles)
  let T = "T"
  let E = text(normalsize, baseline: e.height / 2, "E")
  let X = "X"
  box(T + kern(-0.1667em) + E + kern(-0.125em) + X)
})
#let LaTeX = style(styles => {
  let l = measure(text(10pt, "L"), styles)
  let a = measure(text(7pt, "A"), styles)
  let L = "L"
  let A = text(7pt, baseline: a.height - l.height, "A")
  box(L + kern(-0.36em) + A + kern(-0.15em) + TeX)
})

// Update date
#let date = "2023-05-22"

// Unavailable (last check date)
#show "??": box(text(red, [#date #emoji.crossmark]))
// Tricky
#show "!!": box(text(blue, emoji.drops))
// No idea
#show "?!": box(text(orange, [No idea #emoji.face.unhappy]))
// Tricky figure numbering
#set figure(numbering: n => {
  ([??], [!!], [?!]).at(n - 1)
})
// No prefix
#set ref(supplement: "")

// Justified paragraphs
#set par(justify: true)

// Two-column body
#show: rest => columns(2, rest)

// headcolor
#let headcolor = rgb("004225")

// Run-in sections, like LaTeX \paragraph
#show heading.where(
  level: 1
): it => text(
  size: normalsize,
  weight: "bold",
  fill: headcolor,
  it.body + h(0.67em)
)

// Black raw code
// #show raw.where(block: false): it => { it.text }

// Title
#align(center, link("https://github.com/johanvx/typst-undergradmath")[
  #text(large, headcolor)[*Typst Math for Undergrads*]
])

// Put this here to avoid affecting the title
#show link: underline

This is a Typst port of _#LaTeX Math for Undergrads_ by Jim Hefferon.
The original version is available at #link("https://gitlab.com/jim.hefferon/undergradmath").

= Meaning of annotations
#figure(
  table(
    columns: (1fr, 2fr),
    [??], [This is unavailable. Last check date is #date.],
  )
) <unavailable>
#figure(
  table(
    columns: (1fr, 2fr),
    [!!], [Get this in a tricky way. Need a simpler method.],
  )
) <tricky>
#figure(
  table(
    columns: (1fr, 2fr),
    [?!], [Don't know how to get this.],
  )
) <noidea>

= Rule One
Any mathematics at all, even a single character, gets a mathematical setting.
Thus, for "the value of $x$ is $7$" enter `the value of $x$ is $7$`.

= Template
Your document should contain at least this.

#grid(
  "",
  ```
  -- document body here --
  ```
)

= Common constructs
#align(center, table(
  columns: 2,
  column-gutter: 1.5em,
  cell($x^2$, `x^2`),
  cell([$sqrt(2)$, $root(n, 3)$], [`sqrt(2)`, `root(n, 3)`]),
  cell($x_(i, j)$, `x_(i, j)`),
  cell([$2 / 3$, $2 \/ 3$], [`2 / 3`, `2 \/ 3` or `2 slash 3`]), // Maybe use `slash`?
))

= Calligraphic letters
Use as in `$cal(A)$`.

$ cal(A B C D E F G H I J K L M N O P Q R S T U V W X Y Z) $

Getting script letters is @unavailable.

= Greek
#align(center, table(
  columns: 2,
  column-gutter: 1em,
  cell($alpha$, `alpha`), cell([$xi$, $Xi$], [`xi`, `Xi`]),
  cell($beta$, `beta`), cell($omicron$, `omicron`),
  cell([$gamma$, $Gamma$], [`gamma`, `Gamma`]), cell([$pi$, $Pi$], [`pi`, `Pi`]),
  cell([$delta$, $Delta$], [`delta`, `Delta`]), cell($pi.alt$, `pi.alt`),
  cell($epsilon.alt$, `epsilon.alt`), cell($rho$, `rho`),
  cell($epsilon$, `epsilon`), cell($rho.alt$, `rho.alt`),
  cell($zeta$, `zeta`), cell([$sigma$, $Sigma$], [`sigma`, `Sigma`]),
  cell($eta$, `eta`), cell($\u{03C2}$, [`\u{03C2}` @tricky]),
  cell([$theta$, $Theta$], [`theta`, `Theta`]), cell($tau$, `tau`),
  cell($theta.alt$, `theta.alt`), cell([$upsilon$, $Upsilon$], [`upsilon`, `Upsilon`]),
  cell($iota$, `iota`), cell([$phi.alt$, $Phi$], [`phi.alt`, `Phi`]),
  cell($kappa$, $Kappa$), cell($phi$, `phi`),
  cell([$lambda$, $Lambda$], [`lambda`, `Lambda`]), cell($chi$, `chi`),
  cell($mu$, `mu`), cell([$psi$, $Psi$], [`psi`, `Psi`]),
  cell($nu$, `nu`), cell([$omega$, $Omega$], [`omega`, `Omega`]),
))

= Sets and logic
#align(center, table(
  columns: 3,
  column-gutter: 1em,
  cell($union$, `union`), cell($RR$, [`RR`, `bb(R)`]), cell($forall$, `forall`),
  cell($sect$, `sect`), cell($bb(Z)$, [`ZZ`, `bb(Z)`]), cell($exists$, `exists`),
  cell($subset$, `subset`), cell($bb(Q)$, [`QQ`, `bb(Q)`]), cell($not$, `not`),
  cell($subset.eq$, `subset.eq`), cell($bb(N)$, [`NN`, `bb(N)`]), cell($or$, `or`),
  cell($supset$, `supset`), cell($bb(C)$, [`CC`, `bb(C)`]), cell($and$, `and`),
  cell($supset.eq$, `supset.eq`), cell($diameter$, [`diameter`]), cell($tack.r$, `tack.r`),
  cell($in$, `in`), cell($nothing$, `nothing`), cell($models$, `models`),
  cell($in.not$, `in.not`), cell($alef$, `alef`), cell($without$, `without`),
))

Negate an operator, as in $subset.not$, with `subset.not`.
Get the set complement $A^(sans(c))$ with `A^(sans(c))` (or $A^(complement)$ with `A^(complement)`, or $overline(A)$ with `overline(A)`).

// https://www.ctan.org/tex-archive/fonts/newcomputermodern
//
// README
//
//     Version 3.93
//
//       Provides access to Russian and Greek guillemotleft and guillemotright
//     using the character variant tables cv3 and cv4 respectively.
//
//       The Math fonts provide the character \varnothing, an alternative to \emptyset,
//     through Character Variant cv01. The fontsetup package provides the option
//     'varnothing' to easily switch to the alternative character.

// https://mirrors.sustech.edu.cn/CTAN/fonts/newcomputermodern/doc/newcm-doc.pdf
// The NewComputerModern FontFamily §13.3
// The Math fonts provide the character \varnothing (⌀, U+2300), as an alternative to \emptyset (a slashed zero), through Character Variant cv01.
// The fontsetup package provides the option ‘varnothing’ to easily switch to the alternative character.

/ Remark: Using `diameter` for `\varnothing` may cause some confusion. However, #LaTeX also uses $diameter$ (`\u{2300}`) instead of $\u{2205}$ (`\u{2205}`), see #link("https://mirrors.sustech.edu.cn/CTAN/fonts/newcomputermodern/doc/newcm-doc.pdf")[newcm $section$13.3].
  Another solution is to use `text(font: "Fira Sans", nothing)`, but the resultant glyph $text(font: "Fira Sans", nothing)$ is subtly different from the widely used one.
  Ultimately, the choice is always *your decision*.

= Decorations
#align(center, table(
  columns: 3,
  column-gutter: 1em,
  cell($f'$, [`f'`, `f prime`]), cell($dot(a)$, `dot(a)`), cell($tilde(a)$, `tilde(a)`),
  cell($f prime.double$, `f prime.double`), cell($diaer(a)$, `diaer(a)`), cell($macron(a)$, `macron(a)`),
  cell($Sigma^*$, `Sigma^*`), cell($hat(a)$, `hat(a)`), cell($arrow(a)$, `arrow(a)`),
))

If the decorated letter is $i$ or $j$ then some decorations need `\u{1D6A4}` @tricky and `\u{1D6A5}` @tricky, as in $arrow(\u{1D6A4})$ with `arrow(\u{1D6A4})`.
Some authors use boldface for vectors: `bold(x)`.

Entering `overline(x + y)` produces $overline(x + y)$, and `hat(x + y)` gives $hat(x + y)$.
Comment on an expression as here (there is also `overbrace(..)`).

#align(center, cell(
  $underbrace(x + y, |A|)$,
  `underbrace(x + y, |A|)`,
))

= Dots
Use low dots in a list ${0, 1, 2, ...}$, entered as `{0, 1, 2, ...}`.
Use centered dots in a sum or product $1 + dots.h.c + 100$, entered as  `1 + dots.h.c + 100`.
You can also get vertical dots `dots.v`, diagonal dots `dots.down` and anti-diagonal dots `dots.up`.

= Roman names
Just type them!

#align(center, table(
  columns: 3,
  column-gutter: 1.5em,
  cell($sin$, `sin`), cell($sinh$, `sinh`), cell($arcsin$, `arcsin`),
  cell($cos$, `cos`), cell($cosh$, `cosh`), cell($arccos$, `arccos`),
  cell($tan$, `tan`), cell($tanh$, `tanh`), cell($arctan$, `arctan`),
  cell($sec$, `sec`), cell($coth$, `coth`), cell($min$, `min`),
  cell($csc$, `csc`), cell($det$, `det`), cell($max$, `max`),
  cell($cot$, `cot`), cell($dim$, `dim`), cell($inf$, `inf`),
  cell($exp$, `exp`), cell($ker$, `ker`), cell($sup$, `sup`),
  cell($log$, `log`), cell($deg$, `deg`), cell($liminf$, `liminf`),
  cell($ln$, `ln`), cell($arg$, `arg`), cell($limsup$, `limsup`),
  cell($lg$, `lg`), cell($gcd$, `gcd`), cell($lim$, `lim`),
))

= Other symbols
#align(center, table(
  columns: 3,
  column-gutter: 1.2em,
  cell($<$, [`<`, `lt`]), cell($angle$, `angle`), cell($dot$, [`dot`]),
  cell($<=$, [`<=`, `lt.eq`]), cell($angle.arc$, `angle.arc`), cell($plus.minus$, `plus.minus`),
  cell($>$, [`>`, `gt`]), cell($ell$, `ell`), cell($minus.plus$, `minus.plus`),
  cell($>=$, [`>=`, `gt.eq`]), cell($parallel$, `parallel`), cell($times$, `times`),
  cell($!=$, [`!=`, `eq.not`]), cell($45 degree$, `45 degree`), cell($div$, `div`),
  cell($<<$, [`<<`, `lt.double`]), cell($tilde.equiv$, `tilde.equiv`), cell($*$, [`*`, `ast`]),
  cell($>>$, [`>>`, `gt.double`]), cell($tilde.equiv.not$, `tilde.equiv.not`), cell($divides$, `divides`),
  cell($approx$, `approx`), cell($tilde$, `tilde`), cell($divides.not$, `divides.not`),
  cell($\u{224D}$, [`\u{224D}` @tricky]), cell($tilde.eq$, `tilde.eq`), cell($n!$, `n!`),
  cell($equiv$, `equiv`), cell($tilde.not$, `tilde.not`), cell($diff$, `diff`),
  cell($prec$, `prec`), cell($plus.circle$, `plus.circle`), cell($nabla$, `nabla`),
  cell($prec.eq$, `prec.eq`), cell($minus.circle$, `minus.circle`), cell($planck.reduce$, `planck.reduce`),
  cell($succ$, `succ`), cell($dot.circle$, `dot.circle`), cell($circle.stroked.tiny$, `circle.stroked.tiny`),
  cell($succ.eq$, `succ.eq`), cell($times.circle$, `times.circle`), cell($star$, `star`),
  cell($prop$, `prop`), cell($\u{2298}$, [`\u{2298}` @tricky]), cell($sqrt("")$, `sqrt("")`),
  cell($\u{2250}$, [`\u{2250}` @tricky]), cell($harpoon.tr$, `harpoon.tr`), cell($checkmark$, `checkmark`),
))

Use `a divides b` for the divides relation, $a divides b$, and `a divides.not b` for the negation, $a divides.not b$.
Use `|` to get set builder notation ${a in S | a "is odd"}$ with `{a in S | a "is odd"}`.

= Arrows
#align(center, table(
  columns: 2,
  column-gutter: 1.5em,
  cell($->$, [`->`, `arrow.r`]), cell($|->$, [`|->`, `arrow.r.bar`]),
  cell($arrow.r.not$, `arrow.r.not`), cell($arrow.r.long.bar$, `arrow.r.long.bar`),
  cell($arrow.r.long$, `arrow.r.long`), cell($<-$, [`<-`, `arrow.l`]),
  cell($=>$, [`=>`, `arrow.r.double`]), cell($<->$, [`<->`, `arrow.l.r`]),
  cell($arrow.r.double.not$, `arrow.r.double.not`), cell($arrow.b$, `arrow.b`),
  cell($arrow.r.double.long$, `arrow.r.double.long`), cell($arrow.t$, `arrow.t`),
  cell($arrow.squiggly$, `arrow.squiggly`), cell($arrow.t.b$, `arrow.t.b`),
))

The right arrows in the first column have matching left arrows, such as `arrow.l.not`, and there are some other matches for down arrows, etc.

= Variable-sized operators
The summation $sum_(j = 0)^3 j^2$ `sum_(j = 0)^3 j^2` and the integral $integral_(x = 0)^3 x^2 dif x$ `integral_(x = 0)^3 x^2 dif x` expand when displayed.

$ sum_(j = 0)^3 j^2 qquad integral_(x = 0)^3 x^2 dif x $

These do the same.

#align(center, table(
  columns: 3,
  cell($integral$, `integral`), cell($integral.triple$, `integral.triple`), cell($union.big$, `union.big`),
  cell($integral.double$, `integral.double`), cell($integral.cont$, `integral.cont`), cell($sect.big$, `sect.big`),
))

= Fences
#align(center, table(
  columns: 3,
  column-gutter: 1.5em,
  cell($()$, `()`), cell($angle.l angle.r$, `angle.l angle.r`), cell($abs("")$, `abs("")`),
  cell($[]$, `[]`), cell($floor("")$, `floor("")`), cell($norm("")$, `norm("")`),
  cell(${}$, `{}`), cell($ceil("")$, `ceil("")`),
))

Fix the size with the `lr` function.

#align(center, table(
  columns: 2,
  column-gutter: 0.5em,
  $ lr([sum_(k = 0)^n e^(k^2)], size: #50%) $,
  ```
  lr([sum_(k = 0)^n e^(k^2)], size: #50%)
  ```,
))

To have them grow with the enclosed formula, also use the `lr` function.

#align(center, table(
  columns: 2,
  column-gutter: 1em,
  $ lr(angle.l i, 2^(2^i) angle.r) $,
  ```
  lr(angle.l i, 2^(2^i) angle.r)
  ```,
))

Fences scale by default if entered directly as codepoints, and don't scale automatically if entered as symbol notation.

#align(center, table(
  columns: 2,
  column-gutter: 1em,
  $ (1 / n^(alpha)) $,
  ```
  (1 / n^(alpha))
  ```,
  $ paren.l 1 / n^(alpha) paren.r $,
  ```
  paren.l 1 / n^(alpha) paren.r
  ```,
))

The `lr` function also allows to scale unmatched delimiters and one-side fences.

#align(center, table(
  columns: 2,
  column-gutter: 1em,
  $ lr(frac(dif f, dif x) |)_(x_0) $,
  ```
  lr(frac(dif f, dif x) |)_(x_0)
  ```,
))

= Arrays, Matrices
Get a matrix with the `mat` function. You can pass an array to it.

#align(center, table(
  columns: 2,
  column-gutter: 1em,
  $ mat(a, b; c, d) $,
  ```
  $ mat(a, b; c, d) $
  ```
))

In Typst, #link("https://typst.app/docs/reference/typst/array")[array] is a sequence of values,
while in #LaTeX, array is a matrix without fences, which is `$mat(delim: #none, ..)$` in Typst.

For the determinant use `|A|`, text operator $det$ `det` or `mat(delim: "|", ..)`.

Definition by cases can be easily obtained with the `cases` function.

#align(center, table(
  columns: 2,
  column-gutter: 1em,
  $ f_n = cases(
    a &"if" n = 0,
    r dot f_(n - 1) &"else"
  ) $,
  ```
  $ f_n = cases(
    a &"if" n = 0,
    r dot f_(n - 1) &"else"
  ) $
  ```
))

= Spacing in mathematics
Improve $sqrt(2) x$ to $sqrt(2) thin x$ with a thin space, as in `sqrt(2) thin x`.
Slightly wider are `medium` and `thick` (the three are in ratio $3 : 4 : 5$).
Bigger space is `quad` for $arrow.r quad arrow.l$, which is useful between parts of a display.
Get arbitrary space with the `h` function.
For example, use `#h(2em)` for `\qquad` in #LaTeX and `#h(-0.1667em)` for `\!`.

= Displayed equations
Display equations in a block level using `$ ... $` with at least one space separating the math content and the `$`.

#align(center, table(
  columns: 2,
  column-gutter: 1em,
  $ S = k dot lg W $,
  ```
  $ S = k dot lg W $
  ```,
))

You can break into multiple lines.

#align(center, table(
  columns: 2,
  column-gutter: 1em,
  $ sin(x) = x - x^3 / 3! \
      + x^5 / 5! - dots.h.c $,
  ```
  $ sin(x) = x - x^3 / 3! \
      + x^5 / 5! - dots.h.c $
  ```,
))

Align equations using `&`

#align(center, table(
  columns: 2,
  column-gutter: 1em,
  $ nabla dot bold(D) &= rho \
    nabla dot bold(B) &= 0 $,
  ```
  $ nabla dot bold(D) &= rho \
    nabla dot bold(B) &= 0 $
  ```,
))

(the left or right side of an alignment can be empty).
Get a numbered version by `#set math.equation(numbering: ..)`.

= Calculus examples
The last three here are display style.

#align(center, table(
  align: horizon,
  columns: 2,
  column-gutter: 1em,
  block($f: RR -> RR$),
  ```
  f: RR -> RR
  ```,
  block($"9.8" "m/s"^2$),
  block([`"9.8" "m/s"^2` @tricky]),
  $ lim_(h->0) (f(x+h)-f(x))/h $,
  ```
  lim_(h -> 0) (f(x + h) - f(x)) / h
  ```,
  $ integral x^2 dif x = x^3 \/ 3 + C $,
  ```
  integral x^2 dif x = x^3 \/ 3 + C
  ```,
  $ nabla = bold(i) dif / (dif x) + bold(j) dif / (dif y) + bold(k) dif / (dif z) $,
  ```
  nabla = bold(i) dif / (dif x) + bold(j) dif / (dif y) + bold(k) dif / (dif z)
  ```,
))

= Discrete mathematics examples
For modulo, there is a symbol $equiv$ from `equiv` and a text operator $mod$ from `mod`.

For combinations the binomial symbol $binom(n, k)$ is from `binom(n, k)`.
This resizes to be bigger in a display.

For permutations use $n^(underline(r))$ from `n^(underline(r))` (some authors use $P(n, r)$, or $""_n P_r$ from `""_n P_r`).

= Statistics examples
#align(center, table(
  align: horizon,
  columns: 2,
  block($sigma^2 = sqrt(sum(x_i - mu)^2 \/ N)$),
  ```
  sigma^2 = sqrt(sum(x_i - mu)^2 \/ N)
  ```,
  block($E(X) = mu_X = sum(x_i - P(x_i))$),
  ```
  E(X) = mu_X = sum(x_i - P(x_i))
  ```,
))

The probability density of the normal distribution

$ 1 / sqrt(2 sigma^2 pi) e^(- (x - mu)^2 / (2 sigma^2)) $

comes from this.

#grid(
  "",
  ```
  1 / sqrt(2 sigma^2 pi)
    e^(- (x - mu)^2 / (2 sigma^2))
  ```
)

= For more
See also the Typst Documentation at #link("https://typst.app/docs").

#v(1fr)

#block(
  line(length: 100%, stroke: headcolor) +
  text(headcolor)[johanvx (https://github.com/johanvx) #h(1fr) #date]
)