<!--RENDER=({{!Contact.Phone}} == '4150000000' && {{!Contact.fax}} != '4150000000') || ({{!Contact.Phone}} != '4150000000' && {{!Contact.fax}} == '[undefined]') -->
We have either a defined primary phone number, (415)000-0000, and a fax number that is different than the primary phone number, OR a primary phone number, (415)000-0000, and an undefined fax number
<!--ENDRENDER-->