Many two-person kayaks fill a river surrounded by trees.
Someone left the kayaks unattended at the river.
Just because Many two-person kayaks fill a river surrounded by trees does not mean someone left the kayaks unattended.
exists e1 e2 s1 x1 x2 x3 x4.(Theme(e2,x2) & Actor(e2,x1) & v_fill(e2) & Actor(e1,x4) & n_tree(x4) & Theme(e1,x3) & v_surround(e1) & (x2 = x3) & n_river(x2) & n_kayak(x1) & a_two-person(s1) & Theme(s1,x1) & n_quantity(x1))
exists e2 e1 x1 x2 x3 x4.(n_river(x4) & n_kayak(x2) & Theme(e2,x2) & Actor(e2,x1) & v_leave(e2) & at(e1,x4) & Theme(e1,x3) & v_unattend(e1) & (x2 = x3) & n_person(x1))