### Predefined Constants

The Complex Mathematics Library defines a set of mathematical constants (if they have not been previously defined). They are:

> - M_E (The constant e)
> - M_LOG2E (The logarithm of e to the base of 2)
> - M_LOG10E (The logarithm of e to the base of 10)
> - M_LN2 (The natural logarithm of 2)
> - M_LN10 (The natural logarithm of 10)
> - M_PI (p)
> - M_PI_2 (p / 2)
> - M_PI_4 (p / 4)
> - M_1_PI (1 / p)
> - M_2_PI (2 / p)
> - M_2_SQRTPI (2 divided by the square root of p)
> - M_SQRT2 (The square root of 2)
> - M_SQRT1_2 (The square root of 1 / 2)