Prime-Counting Function/Examples/10

Definition

The value of the prime-counting ($\pi$) function for $10$ is $4$.

Proof

The prime numbers less than $10$ are:

$2, 3, 5, 7$

Hence:

$\map \pi {10} = 4$

$\blacksquare$

Sources

• 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): $\map \pi x$