The man in a white shirt had a flat tire on the back of his bike, and he was repairing it before he could take off again while his friend waited.
The bike can not be ridden.
If a bike has a flat tire, and the owner is repairing it while a friend waits, then it follows that the bike cannot be ridden because otherwise the biker would not repair it right away and inconvenience the friend.
exists e2 e1 p1 s1 s2 x1 x2 x3 x4 x5 x6.(n_friend(x6) & of(x6,x1) & n_male(x1) & n_male(x1) & n_male(x1) & n_male(x1) & n_thing(x4) & n_bike(x5) & of(x5,x1) & n_back(x4) & n_man(x1) & exists e3 p2.(exists e4 p3 s3 s4.(exists e5.(Actor(e5,x6) & v_wait(e5)) & while(e4,p3) & a_again(s4) & Manner(e4,s4) & a_off(s3) & Manner(e4,s3) & Actor(e4,x1) & v_take(e4)) & Topic(e3,p2) & Actor(e3,x1) & v_could(e3)) & before(e2,p1) & Theme(e2,x4) & Actor(e2,x1) & v_repair(e2) & Theme(e1,x3) & Actor(e1,x1) & v_have(e1) & on(x3,x4) & of(x4,x5) & n_tire(x3) & a_flat(s2) & Theme(s2,x3) & in(x1,x2) & n_shirt(x2) & a_white(s1) & Theme(s1,x2))
exists x1.(n_bike(x1) & -exists e1 p1.(exists e2.(Theme(e2,x1) & v_ride(e2)) & Topic(e1,p1) & Actor(e1,x1) & v_can(e1)))