Universe

An implementation of theorem environments for Typst.

Import as

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

Documentation

For detailed guide and documentation see manual.

Features

  • Many default theorem environments:

    • definition,
    • theorem,
    • lemma,
    • statement,
    • proof,
    • corollary,
    • remark,
    • example,
    • algorithm,
    • problem,
    • solution.

    All of them are defined as theofig.with(...). Custom environments can also be defined in terms of generic theofig with appropriate kind, suppliment and numberation.

  • Environments can share counters by having the same kind but different suppliment.

  • Environments can be <label>'d and @reference’d

  • Environments can be customized with show rules as figures with corresponding kinds (with some limitations on nested figures).

  • Environments can be customized using arguments in the corresponding functions.

  • Default environments are translated depending on lang.text to many languages.

Examples

Basic usage

#import "@preview/theofig:0.1.0": *
#set page(paper: "a6", height: auto, margin: 6mm)

#definition[#lorem(5)]<def-1>

#theorem[Lorem, 2025][
  #lorem(12)
]<th-1>

#theorem[
  #lorem(14)
]<th-2>

#proof[
  @th-2 follows immediately from @def-1 and @th-1, which is obvious.
]

Basic usage example. A definition and two theorems are defined. Then they are referenced in the proof.

Custom environments

#import "@preview/theofig:0.1.0": theofig, problem, solution
#set page(paper: "a6", height: auto, margin: 6mm)

#let hard-problem = theofig.with(
  supplement: "Problem", 
  numbering: n => $#n^*$
)

#let hint = theofig.with(
  supplement: "Hint", 
  numbering: none, 
  format-caption: none,
  separator: ":"
)

= Default

#problem[ What $1 + 1$ equals to in $ZZ_2$? ]

#solution[
  Observe that $1 + 1$ is $2$, and $2 mod 2$ is $0$. 
  Hense, the answer is $0$.
]

= Custom

#hard-problem[ Prove that $ZZ_2$ is a field. ]

#hint[ Verify all axioms of a field exaustively. ]

Custom environments example. Defines that adds asterics to the numbering and that has regular (not strong) supplement and separator .

Language support

#import "@preview/theofig:0.1.0": *
#set page(paper: "a6", height: auto, margin: 6mm)

#for lang in theofig-translations.keys() [
  #set text(lang: lang)
  #theorem[#lang][#lorem(5)]
]

Language support example. Theorems in each supported language are displayed.

Per-section numbering

#import "@preview/theofig:0.1.0": *
#set page(paper: "a6", height: auto, margin: 6mm)

#let thm-numbering(n) = numbering("1.1", counter(heading).get().first(), n)
#let eq-numbering(n) = numbering("(1.1)", counter(heading).get().first(), n)

#show figure-where-kind-in(theofig-kinds): set figure(numbering: thm-numbering)
#set math.equation(numbering: eq-numbering)

#set heading(numbering: "1.")
#show heading: it => {
  theofig-reset-counters(theofig-kinds)
  counter(math.equation).update(0)
  it
}

= Addition

#theorem[$ 1 + 1 = 2. $<eq-add-1>]<th-add-1>
#theorem[$ 2 + 2 = 4. $<eq-add-2>]<th-add-2>
#theorem[$ 4 + 4 = 8. $<eq-add-3>]<th-add-3>

= Multiplication

#theorem[$ 1 times 1 =  1. $<eq-mul-1>]<th-mul-1>
#theorem[$ 2 times 2 =  4. $<eq-mul-2>]<th-mul-2>
#theorem[$ 4 times 4 = 16. $<eq-mul-3>]<th-mul-3>

= References
Note that @th-add-2 about @eq-add-2 and
@th-mul-2 about @eq-mul-2 are similar.

Custom numbering example. Section numbering is appended to theorem and equation numbering. Theorem and equation numbering is reset at the start of each section.

Styling

#import "@preview/theofig:0.1.0": *
#set page(paper: "a6", height: auto, margin: 6mm)

// show rule for all (optionally except some)
#show figure-where-kind-in(
  theofig-kinds, except: ("proposition",)
): it => {
  show figure.caption: strong.with(delta: -300)
  show: emph 
  show figure.caption: emph // double emph = no emph
  it
}

// show rule for one
#show figure.where(kind: "remark"): set text(blue)

// styling arguments for one
#let proposition = proposition.with(
  format-caption: (underline, text.with(tracking: 3pt)),
  format-body: smallcaps,
)

#definition[#lorem(15)]
#theorem[#lorem(15)]
#remark[#lorem(15)]

#proposition[#lorem(15)]

Styling example. Definition, theorem, and remark, have regular caption and italic body. Text in remark is blue. Proposition has sparse and underlined caption and body written in small capitals.

Why another one?

There is a number of packages for theorem environments, including all theese. Many of them are similar to this project, but differ in small details of how style customization is handled. Our package offers predefined commands such as #definition, #theorem, #proof, …, together with style customization which can be applied to all or some environments. This project aims to offer a one-import solution to theorem environments with sencible defaults, providing with an intuitive (i.e. following standard typst coding practices) capabilities for customization when it is needed.