Lemmas about divisibility and units #
THIS FILE IS SYNCHRONIZED WITH MATHLIB4. Any changes to this file require a corresponding PR to mathlib4.
In a commutative monoid, an element a divides an element b iff a divides all left
associates of b.
In a commutative monoid, an element a divides an element b iff all
left associates of a divide b.
@[simp]
Units of a monoid divide any element of the monoid.
@[simp]
In a commutative monoid, an element a divides an element b iff a divides all left
associates of b.
@[simp]
In a commutative monoid, an element a divides an element b iff all
left associates of a divide b.
    
theorem
is_unit_of_dvd_unit
    {α : Type u_1}
    [comm_monoid α]
    {x y : α}
    (xy : x ∣ y)
    (hu : is_unit y) :
is_unit x
    
theorem
not_is_unit_of_not_is_unit_dvd
    {α : Type u_1}
    [comm_monoid α]
    {a b : α}
    (ha : ¬is_unit a)
    (hb : a ∣ b) :