Math / LaTeX

Markpion renders mathematical formulas written in LaTeX syntax, using KaTeX. Formulas are converted to MathML, which the system's web engine displays.

Format → Math → Inline Math wraps the selection in $…$, and Format → Math → Math Block puts $$ lines around it (or starts an empty formula).

Inline math

Put the formula between single dollar signs:

The famous identity $e^{i\pi} + 1 = 0$ links five constants.

Display math

Put the formula between double dollar signs on their own lines:

$$
\int_0^1 x^2 \, dx = \frac{1}{3}
$$

A ```math code block works too.

Examples

Fractions and roots: $\frac{a}{b}$, $\sqrt{x^2 + y^2}$
Sub- and superscripts: $x_i^2$, $a_{n+1}$
Greek letters: $\alpha, \beta, \Gamma, \pi$
Sums and limits: $\sum_{k=1}^{n} k = \frac{n(n+1)}{2}$, $\lim_{x \to 0} \frac{\sin x}{x} = 1$

$$
\begin{pmatrix} a & b \\ c & d \end{pmatrix}
\qquad
f(x) = \begin{cases} x & x \ge 0 \\ -x & x < 0 \end{cases}
$$

The Mermaid page has a screenshot of math in the preview.

Supported syntax

KaTeX supports most of LaTeX's math mode: fractions, roots, operators, Greek letters, accents, matrices, cases, aligned and similar environments, and \text{…} inside formulas. The full list is in KaTeX's supported functions. Text-mode LaTeX (documents, packages, \usepackage) isn't supported; this is math inside Markdown.

Limitations and tips

• Dollar signs in text. Because $ starts math, a sentence like "costs $5 or $10" can be read as a formula. Escape the dollar signs: \$5.
• Errors don't break the preview: a formula KaTeX can't parse is shown as its source, in red.
• Appearance depends on your system's MathML support, so formulas can look slightly different on Windows, macOS and Linux.
• To show formulas as plain text, turn off Settings → Preview → Render LaTeX math.

Export

Export	Formulas
Export as HTML	Rendered
Print / Save as PDF	Rendered, as in the preview
Export as Word	Native Word equations you can edit in Word (fractions, roots, scripts, sums, integrals, limits, brackets, Greek letters and operators). A display formula using anything else, such as a matrix or an aligned environment, becomes a picture (its LaTeX is the picture's alt text); an inline one keeps its LaTeX text
Export as LaTeX	Formulas are copied into the .tex file exactly as written ($…$ inline, \[…\] for display formulas), with amsmath and amssymb loaded
Export as PDF	Display formulas ($$…$$) are typeset by MathJax as vector drawings, sharp at any zoom, on every system; this includes matrices, arrows and set symbols. A formula MathJax can't read (an unknown command) stays as LaTeX text. Inline formulas ($…$) are set as text, because PDF text can't flow around drawings: variables in italics, real superscripts and subscripts, fractions as a/b and roots as √. Arrows (\to, \Rightarrow), set symbols (\in, \subseteq, \cup), logic (\forall, \land), brackets such as \langle and \lfloor, and blackboard capitals (\mathbb{R}) are drawn in KaTeX's fonts, the ones the preview uses. A script inside a script made of digits and signs (e^{-x^2}, a_{i_1}) uses superscript and subscript characters; other ones are written in the linear form (e^{x^y} shows e with the superscript x^y). Negated symbols (\notin, \not\subset, \nsubseteq, \nRightarrow) are drawn as in the preview, and an inline matrix is written row by row: \begin{pmatrix} 1 & 2 \\ 3 & 4 \end{pmatrix} becomes (1, 2; 3, 4). An inline formula with an accent (\hat{x}, \vec{v}, \overline{z}) or a command outside this list (such as \binom or \mathcal) stays as LaTeX text

For a PDF with every formula rendered on any system, use Print / Save as PDF.