A group of woman in red shirts are singing.
The women are singing as part of a choir.
A group of woman singing does not imply the woman sing as part of a choir.
exists e1 s1 x1 x2 x3.(Actor(e1,x1) & v_sing(e1) & of(x1,x2) & in(x2,x3) & n_shirt(x3) & a_red(s1) & Theme(s1,x3) & n_woman(x2) & n_group(x1))
exists e1 x1 x2 x3.(n_woman(x1) & as(e1,x2) & of(x2,x3) & n_choir(x3) & n_part(x2) & Actor(e1,x1) & v_sing(e1))