The sky is blue and clear.
The sky is pink
blue and pink are different colors
exists s1 s2 x1.(n_sky(x1) & Theme(s2,x1) & a_clear(s2) & Theme(s1,x1) & a_blue(s1))
exists s1 x1.(n_sky(x1) & Theme(s1,x1) & a_pink(s1))