premise: A lone bike rider navigating a rough terrain course through dirt with trees and grass in the background on a cloud free day.
hypothesis: Somebody is riding a bike on the nature trail.
explanation_1: A course is not a nature trail, it's an area meant to be ridden through on certain vehicles, therefore he is not on a nature trail.
explanation_2: Navigating rough terrain does not necessarily imply a nature trail.
explanation_3: Nature trail and rough terrain are not synonymous.
premise_logic: exists e1 s1 s2 s3 x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12.(n_background(x10) & a_topic(x1) & on(e1,x11) & n_day(x11) & a_free(s3) & Theme(s3,x11) & of(x11,x12) & n_cloud(x12) & with(e1,x7) & subset_of(x9,x7) & in(x9,x10) & n_grass(x9) & subset_of(x8,x7) & n_tree(x8) & through(e1,x6) & n_dirt(x6) & Theme(e1,x4) & Actor(e1,x3) & v_navigate(e1) & n_course(x4) & of(x4,x5) & n_terrain(x5) & a_rough(s2) & Theme(s2,x4) & (x1 = x3) & n_rider(x1) & of(x1,x2) & n_bike(x2) & a_lone(s1) & Theme(s1,x1))
hypothesis_logic: exists e1 x1 x2 x3 x4.(n_nature(x3) & Time(e1,x4) & n_trail(x4) & on(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_ride(e1) & n_bike(x2) & n_person(x1))