A man pick a stone at the sea
The man picked up a stone by the sea.
pick a stone at the sea is a rephrasing of  picked up a stone by the sea.
exists e1 x1 x2 x3.(n_sea(x3) & at(e1,x3) & Theme(e1,x2) & Actor(e1,x1) & v_pick(e1) & n_stone(x2) & n_man(x1))
exists e1 s1 x1 x2 x3.(n_sea(x3) & n_man(x1) & by(e1,x3) & a_up(s1) & Manner(e1,s1) & Theme(e1,x2) & Actor(e1,x1) & v_pick(e1) & n_stone(x2))