T1:=C
T2:=REF(T1,1) AND T1 AND V REF(V,1);
T3:=REF(T2,1) AND T1 AND V REF(V,1);
T4:=REF(T3,1) AND T1 AND V REF(V,1);
XG:REF(T4,1) AND C O AND V REF(V,1);
T1:=C
T2:=REF(T1,1) AND T1 AND V REF(V,1);
T3:=REF(T2,1) AND T1 AND V REF(V,1);
T4:=REF(T3,1) AND T1 AND V REF(V,1);
XG:REF(T4,1) AND C O AND V REF(V,1);