\begin{definition}[Definition:Binomial Coefficient/Technical Note]
The $\LaTeX$ code to render the binomial coefficient $\dbinom n k$ can be written in the following ways:
:<code>\dbinom n k</code>
or:
:<code>\ds {n \choose k}</code>
The <code>\dbinom</code> form is preferred on {{ProofWiki}} because it is simpler.
It is in fact an abbreviated form of <code>\ds \binom n k</code>, which is the preferred construction when <code>\ds</code> is required for another entity in the expression.
While the form <code>\binom n k</code> is valid $\LaTeX$ syntax, it renders the entity in the reduced size inline style: $\binom n k$ which {{ProofWiki}} does not endorse.
To render compound arguments, braces are needed to delimit the parameter when using <code>\dbinom</code>, but (confusingly) not <code>\choose</code>.
For example, to render $\dbinom {a + b} {c d}$ the following can be used:
:<code><nowiki>\dbinom {a + b} {c d}</nowiki></code>
or:
:<code><nowiki>\ds {a + b \choose c d}</nowiki></code> $\ds {a + b \choose c d}$
Again, for consistency across {{ProofWiki}}, the <code>\dbinom</code> form is preferred.
Category:Definitions/Binomial Coefficients
\end{definition}