{ [i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,a,b,c] -> [j] : 1 <= i < j <= 20 };
{ [j] -> [i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v] : 1 <= i < j <= 20 };