premise: A man is working on a computer while two people sit and talk in front.
hypothesis: The two people sat and chatted for a bit while the IT guy removed the virus.
explanation_1: A man working on a computer does not mean he is removing a virus.  All computers don't have viruses.
explanation_2: Sentence 1 doesn't indicate that the man on the computer is an IT guy, nor that the computer has a virus.
explanation_3: A man is working on a computer while two people sit and talk in front doesn't imply that an IT guy removed the virus.
premise_logic: exists e1 p1 x1 x2.(exists e3 e2 x3 x4 x5.(in(e3,x5) & n_front(x5) & Actor(e3,x4) & v_talk(e3) & n_people(x4) & card_eq_2(x4) & Actor(e2,x3) & v_sit(e2) & n_people(x3) & card_eq_2(x3)) & while(e1,p1) & on(e1,x2) & n_computer(x2) & Actor(e1,x1) & v_work(e1) & n_man(x1))
hypothesis_logic: exists e1 e2 p1 x1 x2 x3 x4 x5.(n_virus(x5) & n_guy(x3) & (x3 = x4) & ne_org_it(x4) & n_people(x1) & card_eq_2(x1) & exists e3.(Theme(e3,x5) & Actor(e3,x3) & v_remove(e3)) & while(e2,p1) & for(e2,x2) & n_bit(x2) & Actor(e2,x1) & v_chat(e2) & Actor(e1,x1) & v_sit(e1))