1/(p - 1/(4·p)) - 2/p/(2 - 1/p) + 1/(4·p^2 - 1)
= 1/(4·p^2/(4·p) - 1/(4·p)) - 2/p/(2·p/p - 1/p) + 1/(4·p^2 - 1)
= 1/((4·p^2 - 1)/(4·p)) - 2/p/((2·p - 1)/p) + 1/((2·p + 1)·(2·p - 1))
= 4·p/(4·p^2 - 1) - 2/(2·p - 1) + 1/((2·p + 1)·(2·p - 1))
= 4·p/((2·p + 1)·(2·p - 1)) - 2/(2·p - 1) + 1/((2·p + 1)·(2·p - 1))
= 4·p/((2·p + 1)·(2·p - 1)) - 2·(2·p + 1)/((2·p + 1)·(2·p - 1)) + 1/((2·p + 1)·(2·p - 1))
= (4·p - 2·(2·p + 1) + 1)/((2·p + 1)·(2·p - 1))
= (-1)/((2·p + 1)·(2·p - 1))