Section Compatibility.
Variable gf: rel -> rel.
Hypothesis gf_mon: monotone1 gf.
Structure compatible1 (clo: rel -> rel) : Prop :=
compat1_intro {
compat1_mon: monotone1 clo;
compat1_compat : forall r,
clo (gf r) <1= gf (clo r);
}.
Structure wcompatible1 clo : Prop :=
wcompat1_intro {
wcompat1_mon: monotone1 clo;
wcompat1_wcompat : forall r,
clo (gf r) <1= gf (gupaco1 gf clo r);
}.

Lemma wcompat1_union clo1 clo2
(WCMP1: wcompatible1 clo1)
(WCMP2: wcompatible1 clo2):
wcompatible1 (clo1 \2/ clo2).