A man in a dark shirt has his arm on a females shoulder.
a man with his arm on a woman's shoulder
Women are females. The rest of the information in sentence 2 is mentioned in sentence 1 in the exact manner.
exists e1 s1 s2 x1 x2 x3 x4.(Theme(e1,x3) & Actor(e1,x1) & v_have(e1) & on(x3,x4) & n_shoulder(x4) & a_females(s2) & Theme(s2,x4) & n_arm(x3) & of(x3,x1) & n_male(x1) & in(x1,x2) & n_shirt(x2) & a_dark(s1) & Theme(s1,x2) & n_man(x1))
exists x1 x2 x3 x4.(a_topic(x1) & with(x1,x2) & on(x2,x4) & n_shoulder(x4) & of(x4,x3) & n_woman(x3) & n_arm(x2) & of(x2,x1) & n_male(x1) & n_man(x1))