HP49-HP50 : comparison of two "identical Matrixes"

[Gil]

Suppose I put on the stack
[[ 2 3 ]
[ 5 1 ]]

Then
DUP

Then key 1/x for inverse gives
[[ '-1/13' '3/13' ]
[ '5/13' '-2/13' ]]

Let multiply the initial Matrix by its inverse here, and we get :
:
[[ 1 0 ]
[ 0 1 ]]

Write now
2 IDN

Then compare it by ==

And the answer is 0.

How can I get the correct answer working with integers?

Thanks for your help.

Gil