fact: Record mixin_of (T : poset) := Mixin { mx_lim : chain T -> T; _ : forall (s : chain T) x, x \In s -> x <== mx_lim s; _ : forall (s : chain T) x, (forall y, y \In s -> y <== x) -> mx_lim s <== x}.
imports: mathcomp(ssreflect ssrbool ssrfun ssrnat eqtype seq) pcm(options axioms pred prelude)