NAME
    pi - evaluate pi to specified accuracy

SYNOPSIS
    pi([eps])

TYPES
    eps		nonzero real, defaults to epsilon()

    return	real

DESCRIPTION
    Returns a multiple of eps differing from the true value of pi by
    less than 0.75 eps, and in nearly all cases by less than 0.5 eps.

EXAMPLE
    > print pi(1e-5), pi(1e-10), pi(1e-15), pi(1e-20)
    3.14159 3.1415926536 3.141592653589793 3.14159265358979323846

LIMITS
    eps > 0

LIBRARY
    NUMBER *qpi(NUMBER *eps)

SEE ALSO
    XXX - fill in