Motorcycle police officer rides in a parade.
Police officers are in a Memorial Day parade.
You can not infer it is a Memorial Day parade.
exists x1 x2 x3 x4 x5.(a_topic(x1) & in(x1,x5) & n_parade(x5) & n_ride(x1) & of(x1,x4) & n_officer(x4) & of(x1,x3) & n_police(x3) & (x1 = x2) & ne_nam_motorcycle(x2))
exists p1 x1 x2.(exists x3 x4 x5.(in(x1,x3) & n_parade(x3) & (x3 = x5) & ne_tim_day(x5) & (x3 = x4) & ne_tim_memorial(x4)) & n_officer(x1) & of(x1,x2) & n_police(x2))