# Math Unicode > This skill must be used whenever a response needs mathematical notation — equations, filters, set-builder notation, statistics, calculus, linear algebra, logic, ratios, drops, or counts. Load it before composing, including when the user explicitly mentions math-unicode. Emit terminal-native Unicode inline, never raw LaTeX delimiters or commands. - Skill: `thedixitjain/math-unicode` (Agent Skill) - Install (CLI): `npx skillmds add thedixitjain/math-unicode` - Raw SKILL.md: https://api.skillmd.com/api/skills/thedixitjain/math-unicode/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: thedixitjain (https://skillmd.com/u/thedixitjain) - Updated: 2026-09-09 - Page: https://skillmd.com/skills/thedixitjain/math-unicode --- # math-unicode When emitting mathematical notation in a terminal coding agent (Claude Code, Codex CLI, or similar), **always use Unicode glyphs inline** — never wrap math in `$…$`, `\(...\)`, or `$$...$$`. These terminals do not render LaTeX; raw delimiters appear as plain dollar signs and reduce readability. ## When this skill applies Triggers (use Unicode math): - Equations, formulas, derivations - Filter conditions, set-builder notation - Statistics: probabilities, expectations, distributions - Calculus, linear algebra, logic - Counts, ratios, fractions, drops where precision matters Skip (do not transform): - The user explicitly asks for LaTeX or a `.tex` file - Math inside fenced code blocks (preserve source syntax) - Strings being passed to a system that consumes LaTeX (KaTeX MCP, etc.) ## Glyph cheatsheet ### Greek ``` lowercase α β γ δ ε ζ η θ ι κ λ μ ν ξ ο π ρ σ τ υ φ χ ψ ω uppercase Α Β Γ Δ Ε Ζ Η Θ Ι Κ Λ Μ Ν Ξ Ο Π Ρ Σ Τ Υ Φ Χ Ψ Ω variants ϵ ϑ ϕ ϖ ϱ ς ``` ### Operators ``` arithmetic + − × ÷ ± ∓ · ∗ ⋅ ∘ ⊕ ⊖ ⊗ ⊘ ⊙ big ∑ ∏ ∐ ∫ ∮ ∬ ∭ ⨁ ⨂ ⨅ ⨆ roots √ ∛ ∜ calculus ∂ ∇ Δ ∆ ⅆ ⅇ constants ∞ ∅ ℵ ℶ ``` ### Relations ``` equality = ≠ ≈ ≅ ≡ ≜ ≝ ≐ ∝ ∼ ≃ ≢ order < > ≤ ≥ ≪ ≫ ⋘ ⋙ ⊴ ⊵ set ∈ ∉ ∋ ∌ ⊂ ⊃ ⊆ ⊇ ⊊ ⊋ ⊏ ⊐ ⊑ ⊒ set ops ∪ ∩ ⊎ ⊔ ⊓ ∖ ``` ### Logic & arrows ``` logic ∧ ∨ ¬ ⊕ ⊻ ⊼ ⊽ ⊢ ⊨ ⊥ ⊤ quantifiers ∀ ∃ ∄ ∴ ∵ arrows → ← ↔ ⇒ ⇐ ⇔ ↦ ↪ ↩ ↑ ↓ ⇑ ⇓ ⟶ ⟵ ⟷ ⟹ ⟸ ⟺ ⊸ ``` ### Number sets & brackets ``` sets ℕ ℤ ℚ ℝ ℂ ℙ ℍ 𝔽 brackets ⟨ ⟩ ⌈ ⌉ ⌊ ⌋ ‖ ‖ 〈 〉 ``` ### Sub/superscript glyph blocks ``` superscript ⁰ ¹ ² ³ ⁴ ⁵ ⁶ ⁷ ⁸ ⁹ ⁺ ⁻ ⁼ ⁽ ⁾ ⁱ ⁿ ᵃ ᵇ ᶜ ᵈ ᵉ ᶠ ᵍ ʰ ʲ ᵏ ˡ ᵐ ᵒ ᵖ ʳ ˢ ᵗ ᵘ ᵛ ʷ ˣ ʸ ᶻ subscript ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉ ₊ ₋ ₌ ₍ ₎ ₐ ₑ ₕ ᵢ ⱼ ₖ ₗ ₘ ₙ ₒ ₚ ᵣ ₛ ₜ ᵤ ᵥ ₓ ``` ### Common LaTeX → Unicode | LaTeX | Unicode | LaTeX | Unicode | LaTeX | Unicode | |---|---|---|---|---|---| | `\alpha` | α | `\sum` | ∑ | `\in` | ∈ | | `\beta` | β | `\prod` | ∏ | `\notin` | ∉ | | `\gamma` | γ | `\int` | ∫ | `\subset` | ⊂ | | `\delta` | δ | `\partial` | ∂ | `\subseteq` | ⊆ | | `\epsilon` | ε | `\nabla` | ∇ | `\cup` | ∪ | | `\theta` | θ | `\infty` | ∞ | `\cap` | ∩ | | `\lambda` | λ | `\emptyset` | ∅ | `\setminus` | ∖ | | `\mu` | μ | `\leq` | ≤ | `\wedge` | ∧ | | `\pi` | π | `\geq` | ≥ | `\vee` | ∨ | | `\sigma` | σ | `\neq` | ≠ | `\neg` | ¬ | | `\phi` | φ | `\approx` | ≈ | `\Rightarrow` | ⇒ | | `\omega` | ω | `\equiv` | ≡ | `\Leftrightarrow` | ⇔ | | `\sqrt` | √ | `\propto` | ∝ | `\forall` | ∀ | | `\pm` | ± | `\cdot` | · | `\exists` | ∃ | | `\times` | × | `\to` | → | `\mathbb{R}` | ℝ | ## Style rules ### Rule 1 — Inline math: Unicode, no delimiters Bad: `The filter $f(T; m) = \{(s,r) : n_{s,r} \geq m\}$ produces the cohort.` Good: `The filter f(T; m) = { (s,r) : n_{s,r} ≥ m } produces the cohort.` ### Rule 2 — Block math: own line(s), still no delimiters Bad: $$|Q| / |T| = 5238 / 31075 \approx 16.9\%$$ Good: |Q| / |T| = 5 238 / 31 075 ≈ 16.9 % ### Rule 3 — Subscripts - Single Unicode-renderable index: prefer the glyph (x₁, x₂, xᵢ, xⱼ, xₙ). - Single index with no subscript glyph: use a bare underscore — `I_ν`, `∂_μ`. - Multi-character or grouped subscript: use `_{...}` syntax — the underscore reads unambiguously as a subscript and stays more legible than bracket-style indexing: - `n_{s,r}` ← (s,r) has no Unicode subscript form - `x_max`, `σ_obs` ← multi-letter - Never mix: don't write `x_₁` or `x_{1}` when `x₁` works. ### Rule 4 — Superscripts (powers) - Simple / Unicode-mappable exponent: prefer the glyph — x², x³, xⁿ, eˣ, A⁻¹, and the transpose xᵀ / vᵀ. - Single exponent with no glyph: use a bare caret — `x^ν`, `(z/2)^a`. - Multi-character or expression exponent: use **caret + parentheses**, never `^{...}` — `x^(k+1)`, `x^(i)`, `e^(iπ)`. A bare `x^{T}` / `x^{(i)}` leaks LaTeX source; write `xᵀ` (single glyph) or `x^(i)` (parenthesized). ### Rule 5 — Big operators with selectors Unicode operator + a **bracketed inline selector** — never `_{...}^{...}`. Use `..` for a numeric/expression range, `∈` for set membership, `→` for a limit target, and an equation/condition when that is the natural selector: ``` ∑[i=1..n] aᵢ ∏[k ∈ K] pₖ ∫[a..b] f(x) dx ∫[−∞..∞] e^(−x²) dx ⋃[i=1..n] Aᵢ lim[x→0] f(x) ∑[m₁+...+mₙ=N] c_m ∮[C] f(z) dz Res[z=z₀] f(z) ``` Use ordinary letters for named functions: `Γ`, `B`, `erf`, `det`, `tr`, `Re`, `Im`, `exp`, `log`, `sin`, `cos`, `argmin`. Do not emit `\operatorname`. For a left-scripted named function, use available glyphs such as `₂F₁(a,b;c;z)`; when an index cannot be expressed as one glyph, use readable ASCII notation such as `_{p}F_q` rather than inventing a substitute. ### Rule 6 — Fractions - Inline: `a/b`, `(a + b) / (c + d)` - Block (only when it aids clarity): ``` a + b ───────────── c² + d² ``` ### Rule 7 — Matrices / vectors ASCII art with corner glyphs: ``` A = ⎡ a b ⎤ v = ( v₁ , v₂ , v₃ )ᵀ ⎣ c d ⎦ ``` Declare variable types in prose instead of faking bold or italic: “Here z and n are vectors, and Ω is a matrix.” ### Rule 8 — Tensor indices Tensor indices are indices, not powers. Keep non-mappable tensor indices in bare ASCII form and group only when the index has multiple characters: ``` R^ρ_{σμν} ∂_μ Γ^ρ_{νσ} ``` ### Rule 9 — Piecewise forms and aligned derivations Use the box-drawing brace glyphs for a short piecewise definition; keep equals signs in the same column for a derivation. If those brace glyphs are absent in a reader's font, use a semicolon-separated sentence instead. ``` f(x) = ⎧ x² if x ≥ 0 ⎩ −x if x < 0 aₙ = bₙ + cₙ = dₙ ``` ### Rule 10 — Sets and conditions Prefer set-builder with `|` or `:`: ``` Q = { (s,r) ∈ T : n_{s,r} ≥ 18 ∧ p⁰_{s,r} < 0.9 } ``` ### Rule 11 — Numbers - Thousands: thin space (` `, U+2009) — `5 238`, `34 601` — not commas (locale ambiguous). - Decimal: dot — `16.9 %`. - Percent: space before `%` — `16.9 %` (typographic convention; readable). - Approximations: ≈, ∼. Order of magnitude: ~. Confidence: `x = 5.2 ± 0.3`. ### Rule 12 — When Unicode hurts, fall back explicitly If a glyph chain becomes denser than the LaTeX it replaces, switch to readable ASCII pseudo-LaTeX and annotate it. Example: ``` H(p) = − ∑[x ∈ X] p(x) · log p(x) (∑ = sum over the support X) ``` The reader's comprehension is the only metric. Prefer common, well-supported glyphs. Do not use combining marks or obscure modifier letters just to force a super- or subscript; use readable bare `^x` / `_x` notation instead. Choose whichever form is clearest, then stay consistent within a passage. ### Rule 13 — Plain letters for variables; never style with math-alphanumeric codepoints Write variable names and identifiers with ordinary letters (x, A, Var, RSS). Do **not** reach into the Unicode *Mathematical Alphanumeric Symbols* block (𝐀 bold, 𝐴 italic, 𝓐 script, 𝔸 styled double-struck) to *style* ordinary letters. Those codepoints garble on copy/paste, terminal search, and screen readers — the same failure Claude Code hit in issue #61558. Exception: the standard, semantically meaningful blackboard-bold sets and operators are correct notation, not styling — keep using ℕ ℤ ℚ ℝ ℂ ℙ 𝔽 (number sets) and 𝔼 (expectation). Use those; don't hand-style anything else. ## Quick reference — common forms ``` Mean / std μ ± σ x̄ ± s Probability P(A | B) ℙ(A ∩ B) = ℙ(A) · ℙ(B | A) Expectation 𝔼[X] = ∫ x · f(x) dx Variance Var(X) = 𝔼[X²] − 𝔼[X]² Gradient ∇f = ( ∂f/∂x₁ , ... , ∂f/∂xₙ ) Norm ‖x‖₂ = √(∑[i=1..n] xᵢ²) Big-O T(n) = O(n log n) Limit lim[n → ∞] aₙ = L Sum bounds ∑[i=1..n] i = n(n+1)/2 Quantile q_α = inf{ x : F(x) ≥ α } ``` ## Golden corpus — difficult terminal-native forms These examples are deliberately chosen to exercise non-mappable indices, constrained sums, tensors, special functions, contours, and multiline output. They are normalized terminal forms of standard formulas (including DLMF §10.32.E2, §15.6.E1, §19.19.E1, and §21.2.E1). ``` I_ν(z) = (z/2)^ν / (√π Γ(ν+½)) ∫[0..π] e^(±z cos θ)(sin θ)^(2ν) dθ F(a,b;c;z) = 1 / (Γ(b)Γ(c−b)) ∫[0..1] t^(b−1)(1−t)^(c−b−1) / (1−zt)^a dt T_N(b,z) = ∑[m₁+...+mₙ=N] ((b₁)_{m₁} ··· (bₙ)_{mₙ}) / (m₁! ··· mₙ!) · z₁^(m₁) ··· zₙ^(mₙ) θ(z | Ω) = ∑[n ∈ ℤ^g] exp(2π i(½ n · Ω · n + n · z)) Here z and n are vectors, and Ω is a matrix. R^ρ_{σμν} = ∂_μ Γ^ρ_{νσ} − ∂_ν Γ^ρ_{μσ} + Γ^ρ_{μλ} Γ^λ_{νσ} − Γ^ρ_{νλ} Γ^λ_{μσ} f^(n)(z₀) = n! / (2π i) ∮[C] f(z) / (z−z₀)^(n+1) dz ∂u/∂t + (u · ∇)u = −∇p + νΔu + f, ∇·u = 0 p(x) = exp(−½ (x−μ)ᵀΣ⁻¹(x−μ)) / √((2π)ᵈ det Σ) F(ω) = ∫[−∞..∞] f(t)e^(−iωt) dt f(x) = ⎧ x² if x ≥ 0 ⎩ −x if x < 0 ``` ## Anti-patterns — never emit these in the terminal (Claude Code / Codex) ``` ✗ $f(x) = \sum_{i=1}^{n} x_i$ ✗ \( a^2 + b^2 = c^2 \) ✗ $$\int_0^\infty e^{-x^2} dx = \frac{\sqrt{\pi}}{2}$$ ✗ \[ |Q|/|T| \approx 16.9\% \] ✗ ∑_{i=1}^{n} or ∫_a^b or x^{T} (stacked bounds / brace exponent leak source even without $…$ — write ∑[i=1..n], ∫[a..b], xᵀ) ✗ Let 𝑉𝑎𝑟 = … or matrix 𝐀 = … (math-alphanumeric styling; garbles on copy/search — write Var, A) ``` If asked to produce raw LaTeX (e.g. for a `.tex` file or a KaTeX-rendering tool downstream), do so — and call it out explicitly: *"Raw LaTeX as requested; this will not render in the terminal."* --- **Source:** [`hashgraph-online/awesome-codex-plugins`](https://github.com/hashgraph-online/awesome-codex-plugins) → `plugins/vladimirrott/claude-math/skills/math-unicode/SKILL.md`