Test ribop, h1m and H1mt

> ribop(s[2,1],{2},3);

> ribop(s[2,1],{1},3);

> ribop(s[3,2,1,1],{1,3},4);

> h1m(3,s[1]);

> toh(%);

> toh(h1m(3,h1m(3,h1m(1,1))));

> H1mt(3,s[1]);

> H1mt(3,H1mt(3,H1mt(1,1)));