Some of the hair in his beard are turning grey.
The man's facial hair is changing.
Hair turning gray does imply the man's hair is changing.
exists e1 x1 x2 x3 x4.(n_beard(x3) & of(x3,x2) & n_male(x2) & n_hair(x2) & Theme(e1,x4) & Actor(e1,x1) & v_turn(e1) & n_grey(x4) & of(x1,x2) & in(x2,x3) & n_thing(x1))
exists e1 s1 x1 x2.(n_hair(x2) & a_facial(s1) & Theme(s1,x2) & of(x2,x1) & n_man(x1) & Actor(e1,x2) & v_change(e1))