# Changelog

All notable changes to **scholatex** are documented here.

The format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
and the project adheres to a simple `MAJOR.MINOR` scheme. Entries marked
**BREAKING** change the surface syntax: a document written for an earlier
version may need a small edit, described in the migration note.

## [2.3] — 2026-06-28

### Added

- **Figure drawing: the `<draw>` block.** A figure is described, not
  hand-placed: name the shape and give its measurements, and the coordinates
  are computed trigonometrically and emitted as hard TikZ numbers. One unit
  is one centimetre, so `side:5` draws a 5 cm side; nothing is rescaled.
  - **Triangles** by any classical definition — `equilateral`, `isosceles`,
    `right`, three sides `sides:(a,b,c)`, two sides and the included angle
    `sides:(a,b) angle:t`, two angles and a side `angles:(A,B) side:c`, or
    three sides named one by one (`AB:3 BC:4 CA:5`, the same as
    `sides:(3,4,5)`).
  - **Quadrilaterals** — `square`, `rectangle`, `rhombus`,
    `parallelogram`, `trapezoid`, and `kite` (two pairs of adjacent equal
    sides, the rhombus being the case where both pairs are equal).
  - **Regular polygons** by name from the pentagon up (`pentagon`,
    `hexagon`, `octagon`) or `polygon` with as many points as given.
  - **Circles** by centre and radius or diameter (`circle O radius:3`), the
    radius optionally a named segment (`radius:AB`, the compass span);
    `circle ABC` is the circumscribed circle of three placed points, with
    `inscribed` for the incircle.
- **Coding and measurement.** `marks:on` codes equal sides and right angles
  (off by default); `measures:cm` / `measures:mm` labels each side with its
  length, set parallel to the side. Both are opt-in.
- **Composite figures.** Several figures in one block share their points; a
  figure repeating a point is grafted onto it, and a figure sharing an edge
  deduces that edge's length and is flipped to the far side so the pieces
  abut instead of overlapping.
- **Multi-character point names.** Besides the glued single letters
  (`triangle ABC`), a parenthesised comma-separated list names
  multi-character points: `triangle (O, A0, B0)`. The first character of the
  argument list chooses the form — `(` for the list, anything else for the
  glued form.
- **Loops, interpolation and rotation inside `<draw>`.** A draw block runs
  the same `for VARIABLE in FROM..TO { … }` loops as the rest of the
  language; `#k` and `#{expr}` interpolate point names and measurements;
  `rotate:θ` turns a figure about its first point and `labels:off` hides the
  vertex names — together enough to fan, rosette or step figures round a
  centre.
- **Low-level primitives `point` and `line`.** `point(P)` places a dot at
  coordinates declared with `let P = {x, y}`; `line(A, B)` draws a segment
  between two points (names or literal `{x, y}` pairs), taking `measures:`
  like a figure side. As each coordinate is an ordinary expression, a loop
  can compute endpoints — the building block for free-form drawings such as
  a sun.

### Migration (2.2 → 2.3)

- Purely additive. The `<draw>` block and its primitives are new; existing
  documents are unaffected.

## [2.2] — 2026-06-24

### Added

- **Probability and statistics.** A full vocabulary for a probability
  course: the blackboard operators `PP(...)` ℙ and `EE(...)` 𝔼 (the doubled
  letters, the same rule as the number sets), with the conditional bar
  written `mid` so `PP(A mid B)` spaces correctly. Spread: `var(X)`,
  `std(X)`, `cov(X, Y)`. Distributions: `normal(mu, sigma)` 𝒩(μ, σ²),
  `poisson(lambda)` 𝒫(λ), `binomial(n, p)` ℬ(n, p). Distribution and
  density functions: `repart(X, x)` F\_X(x), `densite(X, x)` f\_X(x).
- **Counting.** The binomial coefficient `C(n, k)` ⁽ⁿₖ⁾ and the arrangement
  `A(n, k)` Aₙᵏ, recognised by their two comma-separated arguments, so a
  one-argument `C(t)` stays an ordinary function. The factorial is
  `factorial(n)` or simply `n!`.
- **Linear-algebra vocabulary.** Named operators on top of the existing
  matrix blocks: `ker(f)`, `im(f)`, `rank(A)`, `span(...)`, `tr(A)`,
  `com(A)`, `eigen(A)` (the spectrum Sp), `adj(A)`. The transpose `transpose(A)`
  sets Aᵀ and the inverse `inv(A)` sets A⁻¹.
- **Differential operators.** `grad(f)`, `div(F)`, `curl(F)` (the named
  operators), the Laplacian `lap(f)` Δf which prefixes its operand without
  parentheses, and the directional derivative `dirderiv(f, u)` ∇_u f.
- **Landau notation.** `bigO(...)` O(·) and `litO(...)` o(·), spelt out so
  the bare letters `o` and `O` remain free as variables.
- **Integral transforms.** `laplace(f)` ℒ{f}, `fourier(f)` ℱ{f}, and their
  inverses `ilaplace(f)`, `ifourier(f)`.
- **Surface and volume integrals.** `surfint(S)` ∯, `volint(V)` ∭ and a
  flux `flux(F, S)`, built on the integral signs unicode-math already
  provides — no new package.
- **Number theory and more sets.** Euler's totient `euler(n)` φ(n), the
  Möbius function `mobius(n)` μ(n), congruence with the keyword `mod`
  (`a equiv b mod n` → a ≡ b (mod n)). Arithmetic helpers `lcm(a, b)`,
  `sign(x)`, `card(A)`, the power set `powerset(A)` 𝒫(A), the integer
  interval `range(1, n)` ⟦1, n⟧, and the keyword `mid` for a spaced bar in
  `set(x mid x > 0)`.
- **Calculation templates.** `taylor(f, x, a, n)` writes the Taylor form
  (template, not a computation), and `jacobian(f, n)` / `hessian(f, n)`
  write the generic partial-derivative matrices.
- **Examples reorganised by domain.** Each mathematical domain is one file:
  `math-analysis` absorbs the vector operators, transforms and Landau
  notations; `math-algebra` absorbs the linear-algebra vocabulary; a new
  `math-probability` covers the probability domain.

### Fixed

- **Extensible parentheses over a fraction.** A parenthesised group holding
  a fraction now grows to full height, so `(a/b)^2` sets ⎛a/b⎞² with tall
  delimiters instead of text-height ones. Plain groups such as `(a+b)` and
  calls like `f(-x)` are untouched.
- **Higher-order differentials.** `d^2y/dx^2` now sets the second-order
  derivative with the upright d throughout; the unparenthesised form is read
  the same as the parenthesised `(d^2 y)/(d x^2)`.
- **Plot axis readability.** A curve crossing an axis no longer blots out
  the tick numbers sitting on it: each tick label is backed by a thin white
  plate, and the axis line runs a little past its last graduation so the
  arrow clears the final number.

### Migration (2.1 → 2.2)

- Purely additive. Existing documents are unaffected; the new vocabulary
  only claims names that were not in use (the two-argument `C(...)` and
  `A(...)`, the doubled `PP`/`EE` already meant the blackboard letters).

## [2.1] — 2026-06-23

### Added

- **Mathematical vocabulary.** The inline mini-language now carries the
  notation a course needs to *state* things, not only compute:
  - Number sets in blackboard bold, doubled-capital ASCIIMath style:
    `NN ZZ DD QQ RR CC`, plus `PP KK HH FF EE UU` for the advanced ones.
  - Quantifiers and connectives: `forall` ∀, `exists` ∃, `and` ∧, `or` ∨,
    `lnot`/`neg` ¬.
  - Implication and equivalence, as words or ASCII arrows: `=>`/`implies`
    ⇒, `<=>`/`iff` ⇔.
  - Set relations and operations: `in subset supset subseteq supseteq cup
    cap setminus emptyset`.
  - The integer part: `floor(x)` ⌊x⌋, `ceil(x)` ⌈x⌉, `round(x)`.
  - One-argument wrappers `set(...)` and `abr(...)` (inner product), and the
    accents `bar`/`conj` (the conjugate–mean–closure overline), `not` (the
    same overline read as logical negation), `hat`, `tilde`.
- **Negation with a single `!`.** A `!` in front of a relation or
  quantifier negates it with the proper struck-through glyph: `!in` ∉,
  `!exists` ∄, `!subset` ⊄, `!subseteq` ⊈, `!equiv` ≢. `!=` keeps its
  meaning "not equal" (≠).
- **Limit arrow.** `arrow(n to +inf)` sets a long right arrow with its
  condition written underneath, for the "uₙ → l" phrasing in running maths.
- **Function studies.** Three tags share one source of truth: `<fn>` builds
  a function object (name, formula, abscissas, derivative signs, variation),
  `<vartab>` renders its variation table, `<plot>` draws its curve through
  pgfplots with pole handling. The table comes in four shapes — full
  (f″, f′, f), classic (f′, f), convexity (f″, f), or a plain value table —
  since the two derivative lines are independent and optional.
- **Section numbering styles.** `num`, `roman`, `ROMAN`, `alpha`, `ALPHA`
  set the counter style of a heading level on its own, with no inherited
  prefix; the default stays hierarchical.

### Changed

- **BREAKING — colours are CamelCase only.** The lowercase colour keywords
  (`red`, `blue`, `green`, `navy`, …) have been removed. There is now a
  single rule: a colour is one of the 151 CSS / svgnames names written in
  CamelCase. The everyday colours are simply the capitalised form (`Red`,
  `Blue`, `Navy`, `Gray`). A lowercase colour now raises an error that names
  its CamelCase replacement.
- **Examples reorganised.** The single `03-math.tex` is split by topic, and
  the showcase set drops its numbering: `text-style`, `containers`,
  `math-language`, `math-analysis`, `math-algebra`, `functions`.

### Migration (1.x / 2.0 → 2.1)

- Replace every lowercase colour keyword with its CamelCase form. The
  mapping is a plain capitalisation:
  `red→Red`, `blue→Blue`, `green→Green`, `navy→Navy`, `orange→Orange`,
  `purple→Purple`, `teal→Teal`, `brown→Brown`, `gray→Gray`, `grey→Grey`,
  `pink→Pink`, `yellow→Yellow`, `black→Black`, `white→White`,
  `violet→Violet`, `cyan→Cyan`, `magenta→Magenta`, `lime→Lime`,
  `olive→Olive`, `aqua→Aqua`, `silver→Silver`, `maroon→Maroon`.
  A sed one-liner for a single file:
  ```
  sed -i -E 's/\b(red|blue|green|navy|orange|purple|teal|brown|gray|grey|pink|yellow|black|white|violet|cyan|magenta|lime|olive|aqua|silver|maroon)\b/\u&/g' file.tex
  ```
  Apply it only to scholatex documents (not to English prose), since it
  capitalises whole words.
- To print a comparison or arrow operator **in running prose** (outside
  `$…$`), double the chevrons: `<<=>>` for ⇔, `<<=` for ≤, `>>=` for ≥.
  Inside a formula nothing changes.

## [2.0] — 2026-06-21

### Changed

- **BREAKING — new escape rules.** To print a special character, double it:
  `<<` `>>` `{{` `}}` `##` give a literal `<` `>` `{` `}` `#`. A backslash is
  now an ordinary character (so `C:\Users` just works) and no longer an
  escape; the old `\<` `\>` `\{` `\}` `\#` forms no longer apply.
- **BREAKING — line break is a tag.** Use `<nextline>` (in text and table
  cells) instead of the old `\\`. In running text a blank line already
  starts a new paragraph, so `<nextline>` is only for a break without a
  paragraph change.

### Security

- Closed-language design: the backslash is inert, so raw LaTeX in the body
  is typeset literally rather than executed. The `untrusted` option runs the
  document's Lua in a restricted sandbox.

## [1.2]

### Fixed

- **Script/fraction precedence.** `^` and `_` now bind tighter than `/`, so
  `x^2/y` is the fraction of `x^2` over `y` (and `1/i^2` is `1` over `i^2`),
  matching ordinary mathematical reading.

### Added

- **Automatic spacing for tall lines.** Consecutive lines with fractions or
  integrals no longer touch; ordinary text is unchanged.

## [1.1]

### Added

- **Maths expansion.** Full integral family (`int`, multiple integrals with
  Fubini ordering, `contourint`, `pvint`, `meanint`), upright functions and
  trigonometry, Leibniz and partial derivatives with ISO 80000-2 upright
  differentials.
- **Operators in display style.** `sum`, `prod`, `lim` keep fractions
  full-size and place limits under the word.
- **Full colour parity.** All 151 xcolor svgnames colours recognised,
  grouped by family in the colour reference.
- **Cross-platform install.** Documented `tlmgr` and manual paths for macOS,
  Linux and Windows.

## [1.0]

- First CTAN release: the tag-based language, text attributes, aliases and
  macros, tables, images, the inline maths mini-language, boxes, the
  named-area grid, lists, control flow.

[2.3]: https://ctan.org/pkg/scholatex
[2.2]: https://ctan.org/pkg/scholatex
[2.1]: https://ctan.org/pkg/scholatex
[2.0]: https://ctan.org/pkg/scholatex
[1.2]: https://ctan.org/pkg/scholatex
[1.1]: https://ctan.org/pkg/scholatex
[1.0]: https://ctan.org/pkg/scholatex