f ( x ) := a x^2 + b x + c

$f (x) : = a x^{2} + b x + c$

x = \frac{ - b \pm \sqrt{ b^2 - 4 a c } }{ 2 a }

$x = \frac{- b \pm \sqrt{b^{2} - 4 a c}}{2 a}$

\cos^2 \theta + \sin^2 \theta = 1

${cos}^{2} θ + {sin}^{2} θ = 1$

\frac{ d }{ d x } \tan x = \frac{ 1 }{ \cos^2 x }

$\frac{d}{d x} tan x = \frac{1}{{cos}^{2} x}$

\angle \mathrm{OAB} = \arccos \left\{ \overrightarrow{\mathrm{OA}} \cdot \overrightarrow{\mathrm{OB}} \right\}

$∠ OAB = arccos {\vec{OA} \cdot \vec{OB}}$

p \perp q \; \text{and} \; r \perp q \ \Rightarrow \ p \parallel r

$p ⟂ q and r ⟂ q \Rightarrow p ∥ r$

f' ( x ) = \lim_{h \to 0} \frac{ f ( x + h ) - f ( x ) }{ h }

$f^{'} (x) = lim_{h \to 0} \frac{f (x + h) - f (x)}{h}$

\erf ( x ) = \frac{ 2 }{ \sqrt{ \pi } } \int_0^x e^{- t^2} \, dt

$erf (x) = \frac{2}{\sqrt{π}} \int_{0}^{x} e^{- t^{2}} d t$

\sum_{n = 1}^\infty \frac{ 1 }{ n^2 } = \frac{ \pi^2 }{ 6 }

$\sum_{n = 1}^{\infty} \frac{1}{n^{2}} = \frac{π^{2}}{6}$

F_{n+1} = F_n + F_{n-1}

$F_{n + 1} = F_{n} + F_{n - 1}$

x \in \mathbb{R}, \ \ z \in \mathbb{C}

$x \in ℝ, z \in ℂ$

\overset{(n)}{X}, \underset{(n)}{X},
        \overbrace{x\times\cdots\times x}, \overbrace{x\times\cdots\times x}^{n}, \underbrace{x\times\cdots\times x}, \underbrace{x\times\cdots\times x}_{n}

$\overset{(n)}{X}, \underset{(n)}{X}, \overset{⏞}{x \times \cdot \cdot \cdot \times x}, \overset{n}{\overset{⏞}{x \times \cdot \cdot \cdot \times x}}, \underset{⏟}{x \times \cdot \cdot \cdot \times x}, \underset{n}{\underset{⏟}{x \times \cdot \cdot \cdot \times x}}$

\overparen{x\times\cdots\times x}, \overparen{x\times\cdots\times x}^{n}, \underparen{x\times\cdots\times x}, \underparen{x\times\cdots\times x}_{n} ,
        \overbracket{x\times\cdots\times x}, \overbracket{x\times\cdots\times x}^{n}, \underbracket{x\times\cdots\times x}, \underbracket{x\times\cdots\times x}_{n}

$\overset{⏜}{x \times \cdot \cdot \cdot \times x}, \overset{n}{\overset{⏜}{x \times \cdot \cdot \cdot \times x}}, \underset{⏝}{x \times \cdot \cdot \cdot \times x}, \underset{n}{\underset{⏝}{x \times \cdot \cdot \cdot \times x}}, \overset{⎴}{x \times \cdot \cdot \cdot \times x}, \overset{n}{\overset{⎴}{x \times \cdot \cdot \cdot \times x}}, \underset{⎵}{x \times \cdot \cdot \cdot \times x}, \underset{n}{\underset{⎵}{x \times \cdot \cdot \cdot \times x}}$

X \overset{f}{\rightarrow} Y \underset{g}{\rightarrow} Z , \ h \eqdef g \circ f

$X \overset{f}{\to} Y \underset{g}{\to} Z, h ≝ g \circ f$

\overline{x + y} , \underline{x + y}, \widehat{x + y}, \overrightarrow{A + B} , \overleftarrow{A + B}

$\overset{̲}{x + y}, \underset{̲}{x + y}, \hat{x + y}, \vec{A + B}, \overset{\leftarrow}{A + B}$

\left. \frac{\pi}{2} \right\} \, \left( x \right) \, \left\{ \frac12 \right.

$, \frac{π}{2}} (x) {\frac{1}{2},$

\Biggl( \biggl( \Bigl( \bigl( ( ) \bigr) \Bigr) \biggr) \Biggr)

$((((()))))$

\mu \left( \bigcup_i E_i \right) = \sum_i \mu ( E_i )

$μ (⋃_{i} E_{i}) = \sum_{i} μ (E_{i})$

_nC_k , \ \binom{n}{k} , \ \binom12 , \ \tbinom{n}{k} , \ \dbinom{n}{k}

${{}_{n}C}_{k}, (\binom{n}{k}), (\binom{1}{2}), (\binom{n}{k}), (\binom{n}{k})$

\forall \epsilon > 0 \exists \delta > 0 \forall y \left[ | y - x | < \delta \Rightarrow | f ( y ) - f ( x ) | < \epsilon \right]

$\forall ϵ > 0 \exists δ > 0 \forall y [| y - x | < δ \Rightarrow | f (y) - f (x) | < ϵ]$

\phi = 1 + \frac{ 1 }{ 1 + \frac{ 1 }{ 1 + \frac{ 1 }{ \ddots } } }

$ϕ = 1 + \frac{1}{1 + \frac{1}{1 + \frac{1}{⋱}}}$

G / \ker f \cong \mathrm{im}\,f

$G / ker f ≅ im f$

\iint_S ( \bm{\nabla} \times \bm{A} ) \cdot d\bm{S} = \oint_C \bm{A} \cdot d\bm{l}

$\iint_{S} (𝛁 \times 𝑨) \cdot d 𝑺 = \oint_{C} 𝑨 \cdot d 𝒍$

\int \mathscr{D}x = \lim_{N \to \infty} \left( \frac{ m }{ 2 \pi i \hbar \Delta t } \right)^\frac{N}{2} \idotsint \prod_{i=1}^{N-1} dx_i

$\int 𝒟︁ x = lim_{N \to \infty} {(\frac{m}{2 π i ℏ Δ t})}^{\frac{N}{2}} \int \cdot \cdot \cdot \int \prod_{i = 1}^{N - 1} d x_{i}$

\int_S f \, d\mu \leq \liminf_{n \to \infty} \int_S f_n \, d\mu

$\int_{S} f d μ \leq \underset{n \to \infty}{lim inf} \int_{S} f_{n} d μ$

\lim_{n \to \infty} P \left( \frac{ S_n - n \mu }{ \sqrt{ n } \sigma } \leq \alpha \right) = \frac{ 1 }{ \sqrt{ 2 \pi } } \int_{- \infty}^\alpha \exp \left( - \frac{ x^2 }{ 2 } \right) \, dx

$lim_{n \to \infty} P (\frac{S_{n} - n μ}{\sqrt{n} σ} \leq α) = \frac{1}{\sqrt{2 π}} \int_{- \infty}^{α} exp (- \frac{x^{2}}{2}) d x$

f: \mathbb{C} \to \mathbb{R} , \ z \mapsto z \bar{z}

$f : ℂ \to ℝ, z \mapsto z \bar{z}$

( \forall \lambda \in \Lambda ) [ A_\lambda \neq \emptyset ] \Rightarrow \prod_{\lambda \in \Lambda} A_\lambda \neq \emptyset

$(\forall λ \in Λ) [A_{λ} \neq ∅︀] \Rightarrow \prod_{λ \in Λ} A_{λ} \neq ∅︀$

A = \left\{z \in \mathbb{C} \;\middle|\; \zeta \left( z \right) = 0 \; \text{and} \; \Re z \neq \frac12 \right\}

$A = {z \in ℂ | ζ (z) = 0 and ℜ z \neq \frac{1}{2}}$

\# \mathbb{N} = \aleph_0

$# ℕ = ℵ_{0}$

\lnot ( P \lor Q) \Leftrightarrow ( \lnot P ) \land ( \lnot Q )

$\neg (P \lor Q) \Leftrightarrow (\neg P) \land (\neg Q)$

0 \longrightarrow L \overset{\phi}{\longrightarrow} M \overset{\psi}{\longrightarrow} N \longrightarrow 0

$0 ⟶ L \overset{ϕ}{⟶} M \overset{ψ}{⟶} N ⟶ 0$

よ: \mathscr{C} \rightarrow {\mathbf{Set}}^{{\mathscr{C}}^\mathrm{op}}

$よ : 𝒞︁ \to {𝐒𝐞𝐭}^{{𝒞︁}^{op}}$

\operatorname{sn} x , \ \vartheta ( z, \tau ) , \ \wp ( z ; \omega_1, \omega_2 )

$sn x, ϑ (z, τ), ℘ (z; ω_{1}, ω_{2})$

m \ddot{\bm{x}} = - m \bm{\nabla} \phi ( \bm{x} )

$m \ddot{𝒙} = - m 𝛁 ϕ (𝒙)$

\Xi = \sum_\mathbf{n} \exp \left\{ - \beta ( E_\mathbf{n} - \mu N_\mathbf{n} ) \right\}

$Ξ = \sum_{𝐧} exp {- β (E_{𝐧} - μ N_{𝐧})}$

i \hbar \frac{ d }{ d t } | \psi \rangle = \hat{H} | \psi \rangle

$i ℏ \frac{d}{d t} | ψ ⟩ = \hat{H} | ψ ⟩$

R_{\mu \nu} - \frac{ 1 }{ 2 } R g_{\mu \nu} = \frac{ 8 \pi G }{ c^4 } T_{\mu \nu}

$R_{μ ν} - \frac{1}{2} R g_{μ ν} = \frac{8 π G}{c^{4}} T_{μ ν}$

- \frac{ 1 }{ 2 } g^{\mu \nu} \partial_\mu \partial_\nu \phi

$- \frac{1}{2} g^{μ ν} \partial_{μ} \partial_{ν} ϕ$

\frac{ \partial \phi }{ \partial t } = D \nabla^2 \phi

$\frac{\partial ϕ}{\partial t} = D \nabla^{2} ϕ$

i \slashed{\partial} \psi - m \psi = 0

$i ∂̸ ψ - m ψ = 0$

\mathscr{O} ( N \ln N )

$𝒪︁ (N ln N)$

\mathfrak{su}(2) \times \mathfrak{u}(1)

$𝔰𝔲 (2) \times 𝔲 (1)$

U^\dagger \, U = U U^\dagger = 1

$U^{†} U = U U^{†} = 1$

\begin{pmatrix}\frac{1}{\sqrt{1-\beta^2}} & -\frac{\beta}{\sqrt{1-\beta^2}} \\ - \frac{\beta}{\sqrt{1-\beta^2}} & \frac{1}{\sqrt{1-\beta^2}}\end{pmatrix} ,
        \begin{matrix} a & b \\ c & d \end{matrix} ,
        \begin{bmatrix} a & b \\ c & d \end{bmatrix} ,
        \begin{vmatrix} a & b \\ c & d \end{vmatrix}

$(\begin{matrix} \frac{1}{\sqrt{1 - β^{2}}} & - \frac{β}{\sqrt{1 - β^{2}}} \\ - \frac{β}{\sqrt{1 - β^{2}}} & \frac{1}{\sqrt{1 - β^{2}}} \end{matrix}), \begin{matrix} a & b \\ c & d \end{matrix}, [\begin{matrix} a & b \\ c & d \end{matrix}], | \begin{matrix} a & b \\ c & d \end{matrix} |$

\begin{align} f ( x ) &= x^2 + 2 x + 1 \\ &= ( x + 1 )^2\end{align}

$\begin{matrix} f (x) & = x^{2} + 2 x + 1 & (1) \\ = (x + 1)^{2} & (2) \end{matrix}$

\begin{align} x &= 93 & y &= 64 & z &= 61 \end{align}

$\begin{matrix} x & = 93 & y & = 64 & z & = 61 & (1) \end{matrix}$

\lambda_\mathrm{Compton} = \frac{ 2 \pi \hbar }{ m c }

$λ_{Compton} = \frac{2 π ℏ}{m c}$

\int Y_{\ell m} ( \Omega ) Y_{\ell' m'} ( \Omega ) \, d^2 \Omega = \delta_{\ell \ell'} \delta_{m m'}

$\int Y_{ℓ m} (Ω) Y_{ℓ^{'} m^{'}} (Ω) d^{2} Ω = δ_{ℓ ℓ^{'}} δ_{m m^{'}}$

{fi}~\mathit{fi}~\mathrm{fi}~\texttt{fi}~\varnothing

$f i 𝑓𝑖 fi fi \emptyset$

\mathcal{C} \times \mathcal{Y}\times\mathcal{P}

$𝒞︀ \times 𝒴︀ \times 𝒫︀$

a := 2 \land b :\equiv 3 \land f : X\to Y

$a : = 2 \land b : \equiv 3 \land f : X \to Y$

f(x):=\begin{cases}0 &\text{if }x\geq 0\\1 &\text{otherwise}\end{cases}

$f (x) : = {\begin{matrix} 0 & if x \geq 0 \\ 1 & otherwise \end{matrix},$

\oint_C \vec{B}\circ \mathrm{d}\vec{\ell} = \mu_0 \left( I_{\mathrm{enc}} + \varepsilon_0 \frac{\mathrm{d}}{\mathrm{d}t} \int_S {\vec{E} \circ \hat{n}}\; \mathrm{d}a \right)

$\oint_{C} \vec{B} \circ d \vec{ℓ} = μ_{0} (I_{enc} + ε_{0} \frac{d}{d t} \int_{S} \vec{E} \circ \hat{n} d a)$