Lemmas about divisibility and units #
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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]
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) :