The sky appears clear.
It's snowing.
If it is snowing, the sky is overcast. The sky will not appear to be clear.
exists e1 p1 x1.(n_sky(x1) & exists s1.(Theme(s1,x1) & a_clear(s1)) & Topic(e1,p1) & Actor(e1,x1) & v_appear(e1))
exists s1 x1.(n_thing(x1) & Theme(s1,x1) & a_snow(s1))