Section RClo.
Inductive rclo6 (clo: rel->rel) (r: rel): rel :=
| rclo6_base
x0 x1 x2 x3 x4 x5
(IN: r x0 x1 x2 x3 x4 x5):
@rclo6 clo r x0 x1 x2 x3 x4 x5
| rclo6_clo'
r' x0 x1 x2 x3 x4 x5
(LE: r' <6= rclo6 clo r)
(IN: clo r' x0 x1 x2 x3 x4 x5):
@rclo6 clo r x0 x1 x2 x3 x4 x5
.

Lemma rclo6_rclo clo r:
rclo6 clo (rclo6 clo r) <6= rclo6 clo r.