A Friend is

A Friend should be Radical;
They should love you when you're unlovable,
Hug you when you're unhuggable,
And bear you when you're unbearable.

But most of all, a Friend should be Mathematical,
They should multiply the joy, Divide the sorrow,
Subtract the past, And add to tomorrow,
Calculate the need deep in your heart,
And always be bigger than the sum of all their parts.