Question : LDAP Query with multiple domains

We have LDAP queries setup for the global address lists that look like the following
(&(&(&(&(objectCategory=*)(mail=*@DOMAIN_1.com)))))

We want the GAL to list domains in the DOMAIN_1.com domain and also a second domain.  I know I need to add the second domain, but can't remember what the syntax is to add the second one.  Googling has so many strange results I figured I would turn here.

Answer : LDAP Query with multiple domains

I can't test this, but the operator for OR is | , so my guess would be to use:
(&(objectCategory=*)(|(mail=*@DOMAIN_1.com)(mail=*@DOMAIN_2.com)))
You have a lot of redundant (&'s