[texhax] align, align*, nonumber and ??

[Christian H. Aastrup]

Hi there!

When I write

\begin{align}
a&=b\nonumber
\\
&=c \nonumber
\\
&=d
\end{align}

I only get at number in the last line. But I want to do this in align and 
need a command that makes a number rather than suppress it

\begin{align*}
a&=b
\\
&=c
\\
&=d \yesnumber
\end{align*}

Does such a \yesnumber command exist?

Kind regards,

Christian Aastrup