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
Any time the price of fuel decreases, Global Airlines' expenses decrease and its income is unaffected. The price of fuel decreased several times last year. Ttherefore, Global Airlines must have made a profit last year.