NOT activation conditions

[McLennan, Neil R]

Hi, 
I have never had to use activation conditions in attribute-resolver.xml before, i have duplicated some definitions with a standard definition getting it via LDAP and another conditional one definition getting value elsewhere. Is that good enough? Or should i put a NOT condition on the LDAP one? 
Is there a simple way of specifying NOT in the activation condition or do i have to create another activation condition with opposite logic?

Neil McLennan