Reusing the result of previous iteration step for comparison

I have the general the following kind of problem. I want to check
somethin
which has to hold for the whole collection. I need it for the selection
comand.
Simplified it is something like that

a = { “tst1” => [[1,0],[0,1]], “tst2” => [[0,0],[1,1]], “tst3” =>
[[0,0],[1,1]]}
a.select {|elemkey,elemattr|
equal = true
elemattr.each {|v| equal = equal && (v[0]==v[1])}
equal == true
}

That works so far, but I think it is not a nice solution. Because I use
the
fact, that I use the variable equal which is defined outside the
each-block.
I am even unsure if that will work anymore with the next ruby-versions
(1.9).
Is there a solution only working with variables
inside the each block? I would prefer a solution with:
a = { “tst1” => [[1,0],[0,1]], “tst2” => [[0,0],[1,1]], “tst3” =>
[[0,0],[1,1]]}
a.select {|elemkey,elemattr|
equal = elemattr.each {|v| ???}
}

Regards,
Tammo

Thank you very match,
that helps.

Regards,
Tammo