Zero Choose Zero/Proof 1

Theorem

$\dbinom 0 0 = 1$

Proof

By Zero Choose n:

$\dbinom 0 n = \delta_{0 n}$

where:

$\dbinom 0 n$ denotes a binomial coefficient

$\delta_{0 n}$ denotes the Kronecker delta.

Hence directly:

$\dbinom 0 0 = 1$

$\blacksquare$