Math

Inkwell has two kinds of mathematics.

Inline math sits in the run of a sentence, for things like n > 0.

Display math gets a line of its own and is numbered. It is a paragraph style, so you can also reach it from the style dropdown or by typing \[.

Select an equation and a math toolbar appears.

The math toolbar

Icon	Action	Type instead
	Superscript	^
	Subscript	_
	Fraction	/
	Square root	sqrt
	Summation	sum
	Product	prod
	Union	bigcup
	Intersection	bigcap
	Binomial	binom
	Integral	int
	Absolute value
	Prime	'
	Roman text (non-italic)

Letters typed into an equation are italicized by default, the way variables are — select some and use Roman text to switch just that selection upright, the way \log and \lim already render automatically. Handy for names and labels inside an equation, like the Bob in I(Bob).

Three dropdowns follow the buttons:

• Style — alternative letterforms: blackboard bold, calligraphic, fraktur, and so on.
• Accent — bars, hats, tildes, vectors and other marks over a symbol.
• Symbol — a browsable panel of mathematical symbols, described below.

Insert Symbol

The Symbol dropdown holds around 180 symbols, for anything you cannot remember the name of. They are grouped into six categories:

• Greek Letters — the lower-case and upper-case alphabets, along with the variant letterforms: \varepsilon, \vartheta, \varphi, and the rest.
• Basic Operators — arithmetic and the everyday constructions: plus-minus, factorial, absolute value, floor and ceiling, roots, binomial coefficients, sums and products.
• Relations — equality, inequality, approximation and similarity, orderings, parallel and perpendicular, divides, and their negated forms.
• Set Theory — membership, subsets and supersets, union and intersection, difference, power set, cardinality, complement, and the quantifiers.
• Logic — negation, conjunction and disjunction, implication, turnstiles and entailment, truth constants, therefore and because.
• Calculus — limits, ordinary and partial derivatives to several orders, single through triple integrals, contour and surface integrals, infimum and supremum, and nabla.

The buttons show the symbol itself and nothing else, so the panel is for browsing when you would recognise the symbol but could not name it. When you can name it, typing is quicker — see below.

If your project already contains mathematics, a Frequently Used row appears above the categories. It is drawn from the equations across the whole project and ordered by how often each symbol appears there, so it settles on the notation your book actually uses. It is not a list of what you inserted most recently, and it holds at most 35 symbols.

There is a second, unrelated Insert Symbol on the main editor toolbar, for dashes and unusual spaces in ordinary text — see Advanced Formatting Features.

Typing rather than clicking

The editor understands mathematical names as you type them: sin, cos, tan, epsilon, gamma, omega, pi, sup, sub, in, and many more. Full LaTeX syntax also works, so if you already know LaTeX you can simply type it.

Typing $x^2$ in ordinary text converts it into inline math automatically.

Turning what you have written into an equation

If the maths is already sitting in your paragraph, select it and press the inline or display math button (or Ctrl+4). Straightforward expressions — E = mc^2, α ≤ β, sin x, anything already written as LaTeX — become equations immediately. Anything described in words, like the absolute value of the inverse of ψ at T, is worked out for you instead, which takes a moment longer.

Numbering and references

Display equations are numbered. To refer to one, type Equation and a picker appears listing the equations in your project; choose one and Inkwell inserts a reference that keeps its number correct if equations are added, removed, or moved.

Settings

Project Settings → Math:

• Font — mathematics needs a font with the right glyph coverage, so ordinary text fonts cannot be used here. Inkwell supplies a range of maths fonts to choose from.
• Number Equations — whether numbering restarts in each chapter or runs continuously through the book.

In Local Settings, a display equation has a single setting, Numbered, for suppressing the number on one particular equation.