monotone(f), f(S) ⊆ S ⊦ μ(f) ⊆ S
monotone(f), f(μ(f)) ⊆ μ(f) ⊦ μ(f) ⊆ f(μ(f)), f(f(μ(f))) ⊆ f(μ(f))
Used terms: f, f(μ(f))