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Mathlib.Algebra.Order.GroupWithZero.Bounds

Lemmas about BddAbove #

theorem BddAbove.range_comp_of_nonneg {α : Type u_1} {β : Type u_2} {γ : Type u_3} [Nonempty α] [Preorder β] [Zero β] [Preorder γ] {f : αβ} {g : βγ} (hf : BddAbove (Set.range f)) (hf0 : 0 f) (hg : MonotoneOn g {x : β | 0 x}) :
BddAbove (Set.range fun (x : α) => g (f x))

A variant of BddAbove.range_comp that assumes that f is nonnegative and g is monotone on nonnegative values.

theorem bddAbove_range_mul {α : Type u_1} {β : Type u_2} [Nonempty α] {u v : αβ} [Preorder β] [Zero β] [Mul β] [PosMulMono β] [MulPosMono β] (hu : BddAbove (Set.range u)) (hu0 : 0 u) (hv : BddAbove (Set.range v)) (hv0 : 0 v) :

If u v : α → β are nonnegative and bounded above, then u * v is bounded above.