equation environment: . \begin{equation} a = 1 \end{equation} .
\begin{equation} a = 1 \end{equation}
. equation* environment: . \begin{equation*} a = 1 \end{equation*} .
\begin{equation*} a = 1 \end{equation*}
. multline environment: . \begin{multline} a = 1 \end{multline} .
\begin{multline} a = 1 \end{multline}
. multline* environment: . \begin{multline*} a = 1 \end{multline*} .
\begin{multline*} a = 1 \end{multline*}
. gather environment: . \begin{gather} a = 1 \end{gather} .
\begin{gather} a = 1 \end{gather}
. gather* environment: . \begin{gather*} a = 1 \end{gather*} .
\begin{gather*} a = 1 \end{gather*}
. align environment: . \begin{align} a = 1 \end{align} .
\begin{align} a = 1 \end{align}
. align* environment: . \begin{align*} a = 1 \end{align*} .
\begin{align*} a = 1 \end{align*}
. alignat environment: . \begin{alignat} a = 1 \end{alignat} .
\begin{alignat} a = 1 \end{alignat}
. alignat* environment: . \begin{alignat*} a = 1 \end{alignat*} .
\begin{alignat*} a = 1 \end{alignat*}
. flalign environment: . \begin{flalign} a = 1 \end{flalign} .
\begin{flalign} a = 1 \end{flalign}
. flalign* environment: . \begin{flalign*} a = 1 \end{flalign*} .
\begin{flalign*} a = 1 \end{flalign*}
. equation environment, with before/after paragraphs: . before \begin{equation} a = 1 \end{equation} after .

before

\begin{equation} a = 1 \end{equation}

after

. equation environment, in list: . - \begin{equation} a = 1 \end{equation} . . `alignat` environment and HTML escaping . \begin{alignat}{3} & d = \frac{1}{1 + 0.2316419x} \quad && a_1 = 0.31938153 \quad && a_2 = -0.356563782 \\ & a_3 = 1.781477937 \quad && a_4 = -1.821255978 \quad && a_5 = 1.330274429 \end{alignat} .
\begin{alignat}{3} & d = \frac{1}{1 + 0.2316419x} \quad && a_1 = 0.31938153 \quad && a_2 = -0.356563782 \\ & a_3 = 1.781477937 \quad && a_4 = -1.821255978 \quad && a_5 = 1.330274429 \end{alignat}
. `alignat*` environment and HTML escaping . \begin{alignat*}{3} & m \quad && \text{módulo} \quad && m>0\\ & a \quad && \text{multiplicador} \quad && 0 \begin{alignat*}{3} & m \quad && \text{módulo} \quad && m>0\\ & a \quad && \text{multiplicador} \quad && 0<a<m\\ & c \quad && \text{constante aditiva} \quad && 0\leq c<m\\ & x_0 \quad && \text{valor inicial} \quad && 0\leq x_0 <m \end{alignat*} .