A person is performing a rollerblading trick as other people skate and run nearby.
The person had never performed the trick  before
If a person is performing a rollerblading trick, it doesn't mean the person had never performed the trick before.
exists e1 e2 p1 x1 x2.(exists e4 e3 s1 x3 x4 x5.(a_nearby(s1) & Manner(e4,s1) & Actor(e4,x5) & v_run(e4) & -(x5 = x3) & n_people(x3) & n_people(x5) & Actor(e3,x3) & v_skate(e3) & -(x3 = x4) & n_people(x4)) & as(e2,p1) & Theme(e2,x2) & Actor(e2,x1) & v_perform(e2) & n_trick(x2) & Actor(e1,x2) & v_rollerblade(e1) & n_person(x1))
exists e1 s1 s2 x1 x2.(n_trick(x2) & n_person(x1) & a_never(s2) & Manner(e1,s2) & a_before(s1) & Manner(e1,s1) & Time(e1,x2) & Actor(e1,x1) & v_perform(e1))