is_opposite_of is opposite of RO:0002604 is_opposite_of is_opposite_of quality true true 'anterior end of organism' is-opposite-of 'posterior end of organism' 'increase in temperature' is-opposite-of 'decrease in temperature' x is the opposite of y if there exists some distance metric M, and there exists no z such as M(x,z) <= M(x,y) or M(y,z) <= M(y,x).