i need to make a attrs to a button when ((a = true and state = done) or (a= false and state = available)
what should i put in the button to make it works?
i tried
<button name = "button_a" string ="Button A" attrs="{'invisible':[('&',('a','=',True),('state','=','done')),('&',('a','=',False),('state','=','available'))]}"/>
and it says there is error