A man, wearing black jeans and a gray shirt, stands in the front of a classroom writing on a chalkboard.
Their teacher writes difficult mathematical calculations
The man writing on the chalkboard is not necessarily the teacher. The man could be writing anything on the chalkboard, not necessarily difficult mathematical calculations.
exists e1 e3 e2 s1 s2 x1 x2 x3 x4 x5 x6 x7 x8 x9.(n_front(x6) & in(e2,x6) & of(x6,x7) & on(e3,x9) & n_chalkboard(x9) & Actor(e3,x8) & v_write(e3) & (x7 = x8) & n_classroom(x7) & Actor(e2,x1) & v_stand(e2) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & subset_of(x5,x3) & n_shirt(x5) & a_gray(s2) & Theme(s2,x5) & subset_of(x4,x3) & n_jeans(x4) & a_black(s1) & Theme(s1,x4) & (x1 = x2) & n_man(x1))
exists e1 s1 s2 x1 x2.(Theme(e1,x1) & Actor(e1,x2) & v_write(e1) & n_calculation(x1) & a_mathematical(s2) & Theme(s2,x1) & a_difficult(s1) & Theme(s1,x1) & n_teacher(x2) & of(x2,x1) & n_thing(x1))