Latex: how to make some text and an equation inseparable?

Question

I mean, I want something like this:

.... bla blabla, the equation is:

\begin{equation}
...
\end{equation}

And I want to finally render the text and the equation together, that is, no page breaks, no figure/whatever else breaks. They have to be inseparable.

How can I do this?

Answer 1

Make sure that they belong to the same paragraph:

.... bla blabla, the equation is:
%
\begin{equation}
...
\end{equation}

The percent sign is the important thing here because it prevents a paragraph end. Since \predisplaypenalty is 10000 by default, the last line of the text will always be on the same page as the equation.

Answer 2

You could probably adapt the solution proposed in tex.stackexchange.com for lists.

Basically, instead of using a \par between your text and the equation, use a custom \par that prevents pagebreak.