EL Expression for Signed Document

I'm trying to conditionally show a button only once the document has been digitally signed using the “digital signature” addon. I've tried a few different EL expressions, but none seem to grab what I want. Here's the condition that the signature tab XHTML uses when the document has a signature:

test=“#{signingStatus.status == 1 || signingStatus.status == 2}”

The value of “signingStatus” is given as #{signActions.signingStatus}