({[i] -> [i+2]} union {[i] -> [i+3]})+;
R := ({[i] -> [i'] : i'=i+3} union {[i] -> [i'] : i'=i+5} union {[i] -> [i'] : i'=i+7})+;
R;
notR := {[i] -> [i'] : i' >= i+3} - R;
notR;
{[i] -> [i'] : i' >= i+3} - notR;