Assigning solve result to function



Hello,

I've got an equation, for example 'x_1 + x_2 = 0' (of course real case
is not so simple, but it's enough for demonstration) and I need to get
function F(x_2) from it.

I tried to use solve for it 'solve(x_1 + x_2 = 0, x_1)' and get 'x_1 = -
x_2'. Now I couldn't find, how to extract right part of solve result
into function. Just 'F(x_2) := solve(x_1 + x_2 = 0, x_1)' of course
doesn't work, it results to 'x_1 = -x_2' instead of wanted '- x_2'.

Can anybody help with it? And maybe I'm on the wrong path and shouldn't
use 'solve' for it?

Thanks in advance.

-- 
Best Regards,
Dmitry Vinokurov
<d.vinokuroff at gmail.com>