In line: define $$\mathbf{Y}$$ as the network edges, ...
in block:
$$
P(\mathbf{Y} = \mathbf{y}|\mathbf{X}) = exp[{\theta } ^{T} g(\mathbf{y},\mathbf{X})]/k(\theta )
$$
Block equations:
$$
\begin{align}
\mbox{Union: } & A\cup B = {x\mid x\in A \mbox{ or } x\in B} \\
\mbox{Concatenation: } & A\circ B = {xy\mid x\in A \mbox{ and } y\in B} \\
\mbox{Star: } & A^\star = {x_1x_2\ldots x_k \mid k\geq 0 \mbox{ and each } x_i\in A} \\
\end{align}
$$
Yet another set of block equations:
$$
\begin{align*}
2x - 5y &= 8 \\
3x + 9y &= -12
\end{align*}
$$
In line: define$$\mathbf{Y}$$ as the network edges, ...
in block:
Block equations:
Yet another set of block equations:s