Someone named Bryant is in Africa.
I am Kelly Bryant.
Therefore, I am in Africa.
While the first two premises are true, this argument is clearly false.
(A) being Bryant, my surname, (B) being Africa, and (C) being myself, (A) is in (B), and (C) is a (A), so (C) must be in (B).
Unfortunately, there is another Bryant, my sister Stacey, who is currently spending her weeks working in Uganda, and her weekends white water rafting the Nile. I, the other Bryant, am stuck in high school in Coquitlam, making this valid, but faulty logic.
Using disjunctive syllogism, however, you could say:
Either Kelly Bryant or Stacey Bryant is in Africa.
Kelly Bryant is in Port Coquitlam.
Therefore, Stacey Bryant is in Africa.
The above argument is both sound and valid, as I just got off the phone with my lucky sister, who called from her hut in Mbarara, while I lay in bed in Port Coquitlam.