Paleomycologists, scientists who study ancient forms of fungi, are invariably acquainted with the scholarly publications of all other paleomycologists  Professor Mansour is acquainted with the scholarly publications of Professor DeAngelis, who is a paleomycologist
Ttherefore, Professor Mansour must also be a paleomycologist
All employees of Global Airlines can participate in its retirement plan after they have been with the company a year or more. Gavin has been with Global Airlines for three years. We can ttherefore be sure that he participates in Global's retirement plan.