Validation rule with two OR functions

I only want users with EITHER Test Invoice or Test Invoice 2 permission sets to change an opportunity to a closed stage. I have tried this:

AND(

$Permission.Test_Invoice =false,

$Permission.Test_Invoice_2=false,

OR(

ISPICKVAL(StageName , "Ready to Invoice"),

ISPICKVAL(StageName , "Credited"),

ISPICKVAL(StageName , "Ready to Estimate"),

ISPICKVAL(StageName , "Part Invoiced"),

ISPICKVAL(StageName , "Closed Won")

)) 

But it doesn't allow the correct user to change the stage. I've definitely got the first bit wrong, but it doesn't work if I use OR so I'm not sure what to change it to.

#Formulas