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bounded_lattice_hom.as_boolring (f : bounded_lattice_hom α β) : as_boolring α →+* as_boolring β
{ to_fun := to_boolring ∘ f ∘ of_boolring, map_zero' := f.map_bot', map_one' := f.map_top', map_add' := map_symm_diff' f, map_mul' := f.map_inf' }
def
bounded_lattice_hom.as_boolring
algebra.ring
src/algebra/ring/boolean_ring.lean
[ "algebra.punit_instances", "tactic.abel", "tactic.ring", "order.hom.lattice" ]
[ "as_boolring", "bounded_lattice_hom", "map_symm_diff'", "of_boolring", "to_boolring" ]
Turn a bounded lattice homomorphism from Boolean algebras `α` to `β` into a ring homomorphism from `α` to `β` considered as Boolean rings.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bounded_lattice_hom.as_boolring_id : (bounded_lattice_hom.id α).as_boolring = ring_hom.id _
rfl
lemma
bounded_lattice_hom.as_boolring_id
algebra.ring
src/algebra/ring/boolean_ring.lean
[ "algebra.punit_instances", "tactic.abel", "tactic.ring", "order.hom.lattice" ]
[ "as_boolring", "bounded_lattice_hom.id", "ring_hom.id" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bounded_lattice_hom.as_boolring_comp (g : bounded_lattice_hom β γ) (f : bounded_lattice_hom α β) : (g.comp f).as_boolring = g.as_boolring.comp f.as_boolring
rfl
lemma
bounded_lattice_hom.as_boolring_comp
algebra.ring
src/algebra/ring/boolean_ring.lean
[ "algebra.punit_instances", "tactic.abel", "tactic.ring", "order.hom.lattice" ]
[ "as_boolring", "bounded_lattice_hom" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
order_iso.as_boolalg_as_boolring (α : Type*) [boolean_algebra α] : as_boolalg (as_boolring α) ≃o α
⟨of_boolalg.trans of_boolring, λ a b, of_boolring_le_of_boolring_iff.trans of_boolalg_mul_of_boolalg_eq_left_iff⟩
def
order_iso.as_boolalg_as_boolring
algebra.ring
src/algebra/ring/boolean_ring.lean
[ "algebra.punit_instances", "tactic.abel", "tactic.ring", "order.hom.lattice" ]
[ "as_boolalg", "as_boolring", "boolean_algebra", "of_boolring" ]
Order isomorphism between `α` considered as a Boolean ring considered as a Boolean algebra and `α`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ring_equiv.as_boolring_as_boolalg (α : Type*) [boolean_ring α] : as_boolring (as_boolalg α) ≃+* α
{ map_mul' := λ a b, rfl, map_add' := of_boolalg_symm_diff, ..of_boolring.trans of_boolalg }
def
ring_equiv.as_boolring_as_boolalg
algebra.ring
src/algebra/ring/boolean_ring.lean
[ "algebra.punit_instances", "tactic.abel", "tactic.ring", "order.hom.lattice" ]
[ "as_boolalg", "as_boolring", "boolean_ring", "of_boolalg", "of_boolalg_symm_diff" ]
Ring isomorphism between `α` considered as a Boolean algebra considered as a Boolean ring and `α`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_right [distrib R] {a b c : R} : commute a b → commute a c → commute a (b + c)
semiconj_by.add_right
theorem
commute.add_right
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "distrib", "semiconj_by.add_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_left [distrib R] {a b c : R} : commute a c → commute b c → commute (a + b) c
semiconj_by.add_left
theorem
commute.add_left
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "distrib", "semiconj_by.add_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bit0_right [distrib R] {x y : R} (h : commute x y) : commute x (bit0 y)
h.add_right h
lemma
commute.bit0_right
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "distrib" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bit0_left [distrib R] {x y : R} (h : commute x y) : commute (bit0 x) y
h.add_left h
lemma
commute.bit0_left
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "distrib" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bit1_right [non_assoc_semiring R] {x y : R} (h : commute x y) : commute x (bit1 y)
h.bit0_right.add_right (commute.one_right x)
lemma
commute.bit1_right
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "commute.one_right", "non_assoc_semiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bit1_left [non_assoc_semiring R] {x y : R} (h : commute x y) : commute (bit1 x) y
h.bit0_left.add_left (commute.one_left y)
lemma
commute.bit1_left
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "commute.one_left", "non_assoc_semiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_self_sub_mul_self_eq [non_unital_non_assoc_ring R] {a b : R} (h : commute a b) : a * a - b * b = (a + b) * (a - b)
by rw [add_mul, mul_sub, mul_sub, h.eq, sub_add_sub_cancel]
lemma
commute.mul_self_sub_mul_self_eq
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "non_unital_non_assoc_ring" ]
Representation of a difference of two squares of commuting elements as a product.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_self_sub_mul_self_eq' [non_unital_non_assoc_ring R] {a b : R} (h : commute a b) : a * a - b * b = (a - b) * (a + b)
by rw [mul_add, sub_mul, sub_mul, h.eq, sub_add_sub_cancel]
lemma
commute.mul_self_sub_mul_self_eq'
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "non_unital_non_assoc_ring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_self_eq_mul_self_iff [non_unital_non_assoc_ring R] [no_zero_divisors R] {a b : R} (h : commute a b) : a * a = b * b ↔ a = b ∨ a = -b
by rw [← sub_eq_zero, h.mul_self_sub_mul_self_eq, mul_eq_zero, or_comm, sub_eq_zero, add_eq_zero_iff_eq_neg]
lemma
commute.mul_self_eq_mul_self_iff
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "mul_eq_zero", "mul_self_eq_mul_self_iff", "no_zero_divisors", "non_unital_non_assoc_ring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_right : commute a b → commute a (- b)
semiconj_by.neg_right
theorem
commute.neg_right
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "semiconj_by.neg_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_right_iff : commute a (-b) ↔ commute a b
semiconj_by.neg_right_iff
theorem
commute.neg_right_iff
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "semiconj_by.neg_right_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_left : commute a b → commute (- a) b
semiconj_by.neg_left
theorem
commute.neg_left
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "semiconj_by.neg_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_left_iff : commute (-a) b ↔ commute a b
semiconj_by.neg_left_iff
theorem
commute.neg_left_iff
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "semiconj_by.neg_left_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_one_right (a : R) : commute a (-1)
semiconj_by.neg_one_right a
theorem
commute.neg_one_right
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "semiconj_by.neg_one_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_one_left (a : R): commute (-1) a
semiconj_by.neg_one_left a
theorem
commute.neg_one_left
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "semiconj_by.neg_one_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sub_right : commute a b → commute a c → commute a (b - c)
semiconj_by.sub_right
theorem
commute.sub_right
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "semiconj_by.sub_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sub_left : commute a c → commute b c → commute (a - b) c
semiconj_by.sub_left
theorem
commute.sub_left
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute", "semiconj_by.sub_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_self_sub_mul_self [comm_ring R] (a b : R) : a * a - b * b = (a + b) * (a - b)
(commute.all a b).mul_self_sub_mul_self_eq
theorem
mul_self_sub_mul_self
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "comm_ring", "commute.all" ]
Representation of a difference of two squares in a commutative ring as a product.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_self_sub_one [non_assoc_ring R] (a : R) : a * a - 1 = (a + 1) * (a - 1)
by rw [←(commute.one_right a).mul_self_sub_mul_self_eq, mul_one]
lemma
mul_self_sub_one
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute.one_right", "mul_one", "non_assoc_ring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_self_eq_mul_self_iff [comm_ring R] [no_zero_divisors R] {a b : R} : a * a = b * b ↔ a = b ∨ a = -b
(commute.all a b).mul_self_eq_mul_self_iff
lemma
mul_self_eq_mul_self_iff
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "comm_ring", "commute.all", "no_zero_divisors" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_self_eq_one_iff [non_assoc_ring R] [no_zero_divisors R] {a : R} : a * a = 1 ↔ a = 1 ∨ a = -1
by rw [←(commute.one_right a).mul_self_eq_mul_self_iff, mul_one]
lemma
mul_self_eq_one_iff
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "commute.one_right", "mul_one", "mul_self_eq_mul_self_iff", "no_zero_divisors", "non_assoc_ring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_eq_self_iff [ring R] [no_zero_divisors R] (u : Rˣ) : u⁻¹ = u ↔ u = 1 ∨ u = -1
begin rw inv_eq_iff_mul_eq_one, simp only [ext_iff], push_cast, exact mul_self_eq_one_iff end
lemma
units.inv_eq_self_iff
algebra.ring
src/algebra/ring/commute.lean
[ "algebra.ring.semiconj", "algebra.ring.units", "algebra.group.commute" ]
[ "inv_eq_iff_mul_eq_one", "mul_self_eq_one_iff", "no_zero_divisors", "ring" ]
In the unit group of an integral domain, a unit is its own inverse iff the unit is one or one's additive inverse.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ring_hom_comp_triple (σ₁₂ : R₁ →+* R₂) (σ₂₃ : R₂ →+* R₃) (σ₁₃ : out_param (R₁ →+* R₃)) : Prop
(comp_eq : σ₂₃.comp σ₁₂ = σ₁₃)
class
ring_hom_comp_triple
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "comp_eq" ]
Class that expresses the fact that three ring homomorphisms form a composition triple. This is used to handle composition of semilinear maps.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_apply [ring_hom_comp_triple σ₁₂ σ₂₃ σ₁₃] {x : R₁} : σ₂₃ (σ₁₂ x) = σ₁₃ x
ring_hom.congr_fun comp_eq x
lemma
ring_hom_comp_triple.comp_apply
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "comp_eq", "ring_hom.congr_fun", "ring_hom_comp_triple" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ring_hom_inv_pair (σ : R₁ →+* R₂) (σ' : out_param (R₂ →+* R₁)) : Prop
(comp_eq : σ'.comp σ = ring_hom.id R₁) (comp_eq₂ : σ.comp σ' = ring_hom.id R₂)
class
ring_hom_inv_pair
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "comp_eq", "ring_hom.id" ]
Class that expresses the fact that two ring homomorphisms are inverses of each other. This is used to handle `symm` for semilinear equivalences.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_apply_eq {x : R₁} : σ' (σ x) = x
by { rw [← ring_hom.comp_apply, comp_eq], simp }
lemma
ring_hom_inv_pair.comp_apply_eq
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "comp_eq", "ring_hom.comp_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_apply_eq₂ {x : R₂} : σ (σ' x) = x
by { rw [← ring_hom.comp_apply, comp_eq₂], simp }
lemma
ring_hom_inv_pair.comp_apply_eq₂
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom.comp_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ids : ring_hom_inv_pair (ring_hom.id R₁) (ring_hom.id R₁)
⟨rfl, rfl⟩
instance
ring_hom_inv_pair.ids
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom.id", "ring_hom_inv_pair" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
triples {σ₂₁ : R₂ →+* R₁} [ring_hom_inv_pair σ₁₂ σ₂₁] : ring_hom_comp_triple σ₁₂ σ₂₁ (ring_hom.id R₁)
⟨by simp only [comp_eq]⟩
instance
ring_hom_inv_pair.triples
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "comp_eq", "ring_hom.id", "ring_hom_comp_triple", "ring_hom_inv_pair" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
triples₂ {σ₂₁ : R₂ →+* R₁} [ring_hom_inv_pair σ₁₂ σ₂₁] : ring_hom_comp_triple σ₂₁ σ₁₂ (ring_hom.id R₂)
⟨by simp only [comp_eq₂]⟩
instance
ring_hom_inv_pair.triples₂
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom.id", "ring_hom_comp_triple", "ring_hom_inv_pair" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
of_ring_equiv (e : R₁ ≃+* R₂) : ring_hom_inv_pair (↑e : R₁ →+* R₂) ↑e.symm
⟨e.symm_to_ring_hom_comp_to_ring_hom, e.symm.symm_to_ring_hom_comp_to_ring_hom⟩
lemma
ring_hom_inv_pair.of_ring_equiv
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom_inv_pair" ]
Construct a `ring_hom_inv_pair` from both directions of a ring equiv. This is not an instance, as for equivalences that are involutions, a better instance would be `ring_hom_inv_pair e e`. Indeed, this declaration is not currently used in mathlib. See note [reducible non-instances].
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
symm (σ₁₂ : R₁ →+* R₂) (σ₂₁ : R₂ →+* R₁) [ring_hom_inv_pair σ₁₂ σ₂₁] : ring_hom_inv_pair σ₂₁ σ₁₂
⟨ring_hom_inv_pair.comp_eq₂, ring_hom_inv_pair.comp_eq⟩
lemma
ring_hom_inv_pair.symm
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom_inv_pair" ]
Swap the direction of a `ring_hom_inv_pair`. This is not an instance as it would loop, and better instances are often available and may often be preferrable to using this one. Indeed, this declaration is not currently used in mathlib. See note [reducible non-instances].
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ids : ring_hom_comp_triple (ring_hom.id R₁) σ₁₂ σ₁₂
⟨by { ext, simp }⟩
instance
ring_hom_comp_triple.ids
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom.id", "ring_hom_comp_triple" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_ids : ring_hom_comp_triple σ₁₂ (ring_hom.id R₂) σ₁₂
⟨by { ext, simp }⟩
instance
ring_hom_comp_triple.right_ids
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom.id", "ring_hom_comp_triple" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ring_hom_surjective (σ : R₁ →+* R₂) : Prop
(is_surjective : function.surjective σ)
class
ring_hom_surjective
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[]
Class expressing the fact that a `ring_hom` is surjective. This is needed in the context of semilinear maps, where some lemmas require this.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ring_hom.is_surjective (σ : R₁ →+* R₂) [t : ring_hom_surjective σ] : function.surjective σ
t.is_surjective
lemma
ring_hom.is_surjective
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom_surjective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
inv_pair {σ₁ : R₁ →+* R₂} {σ₂ : R₂ →+* R₁} [ring_hom_inv_pair σ₁ σ₂] : ring_hom_surjective σ₁
⟨λ x, ⟨σ₂ x, ring_hom_inv_pair.comp_apply_eq₂⟩⟩
instance
ring_hom_surjective.inv_pair
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom_inv_pair", "ring_hom_surjective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ids : ring_hom_surjective (ring_hom.id R₁)
⟨is_surjective⟩
instance
ring_hom_surjective.ids
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom.id", "ring_hom_surjective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp [ring_hom_comp_triple σ₁₂ σ₂₃ σ₁₃] [ring_hom_surjective σ₁₂] [ring_hom_surjective σ₂₃] : ring_hom_surjective σ₁₃
{ is_surjective := begin have := σ₂₃.is_surjective.comp σ₁₂.is_surjective, rwa [← ring_hom.coe_comp, ring_hom_comp_triple.comp_eq] at this, end }
lemma
ring_hom_surjective.comp
algebra.ring
src/algebra/ring/comp_typeclasses.lean
[ "algebra.ring.equiv" ]
[ "ring_hom.coe_comp", "ring_hom_comp_triple", "ring_hom_surjective" ]
This cannot be an instance as there is no way to infer `σ₁₂` and `σ₂₃`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
distrib (R : Type*) extends has_mul R, has_add R
(left_distrib : ∀ a b c : R, a * (b + c) = a * b + a * c) (right_distrib : ∀ a b c : R, (a + b) * c = a * c + b * c)
class
distrib
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "left_distrib", "right_distrib" ]
A typeclass stating that multiplication is left and right distributive over addition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_distrib_class (R : Type*) [has_mul R] [has_add R]
(left_distrib : ∀ a b c : R, a * (b + c) = a * b + a * c)
class
left_distrib_class
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "left_distrib" ]
A typeclass stating that multiplication is left distributive over addition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_distrib_class (R : Type*) [has_mul R] [has_add R]
(right_distrib : ∀ a b c : R, (a + b) * c = a * c + b * c)
class
right_distrib_class
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "right_distrib" ]
A typeclass stating that multiplication is right distributive over addition.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
distrib.left_distrib_class (R : Type*) [distrib R] : left_distrib_class R
⟨distrib.left_distrib⟩
instance
distrib.left_distrib_class
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "distrib", "left_distrib_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
distrib.right_distrib_class (R : Type*) [distrib R] : right_distrib_class R
⟨distrib.right_distrib⟩
instance
distrib.right_distrib_class
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "distrib", "right_distrib_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
left_distrib [has_mul R] [has_add R] [left_distrib_class R] (a b c : R) : a * (b + c) = a * b + a * c
left_distrib_class.left_distrib a b c
lemma
left_distrib
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "left_distrib_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
right_distrib [has_mul R] [has_add R] [right_distrib_class R] (a b c : R) : (a + b) * c = a * c + b * c
right_distrib_class.right_distrib a b c
lemma
right_distrib
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "right_distrib_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
distrib_three_right [has_mul R] [has_add R] [right_distrib_class R] (a b c d : R) : (a + b + c) * d = a * d + b * d + c * d
by simp [right_distrib]
lemma
distrib_three_right
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "right_distrib", "right_distrib_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
non_unital_non_assoc_semiring (α : Type u) extends add_comm_monoid α, distrib α, mul_zero_class α
class
non_unital_non_assoc_semiring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "add_comm_monoid", "distrib", "mul_zero_class" ]
A not-necessarily-unital, not-necessarily-associative semiring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
non_unital_semiring (α : Type u) extends non_unital_non_assoc_semiring α, semigroup_with_zero α
class
non_unital_semiring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "non_unital_non_assoc_semiring", "semigroup_with_zero" ]
An associative but not-necessarily unital semiring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
non_assoc_semiring (α : Type u) extends non_unital_non_assoc_semiring α, mul_zero_one_class α, add_comm_monoid_with_one α
class
non_assoc_semiring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "add_comm_monoid_with_one", "mul_zero_one_class", "non_unital_non_assoc_semiring" ]
A unital but not-necessarily-associative semiring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
semiring (α : Type u) extends non_unital_semiring α, non_assoc_semiring α, monoid_with_zero α
class
semiring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "monoid_with_zero", "non_assoc_semiring", "non_unital_semiring" ]
A semiring is a type with the following structures: additive commutative monoid (`add_comm_monoid`), multiplicative monoid (`monoid`), distributive laws (`distrib`), and multiplication by zero law (`mul_zero_class`). The actual definition extends `monoid_with_zero` instead of `monoid` and `mul_zero_class`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_add_one_eq_two : 1 + 1 = (2 : α)
rfl
lemma
one_add_one_eq_two
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_one_mul [right_distrib_class α] (a b : α) : (a + 1) * b = a * b + b
by rw [add_mul, one_mul]
lemma
add_one_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "one_mul", "right_distrib_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_add_one [left_distrib_class α] (a b : α) : a * (b + 1) = a * b + a
by rw [mul_add, mul_one]
lemma
mul_add_one
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "left_distrib_class", "mul_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_add_mul [right_distrib_class α] (a b : α) : (1 + a) * b = b + a * b
by rw [add_mul, one_mul]
lemma
one_add_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "one_mul", "right_distrib_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_one_add [left_distrib_class α] (a b : α) : a * (1 + b) = a + a * b
by rw [mul_add, mul_one]
lemma
mul_one_add
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "left_distrib_class", "mul_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
two_mul [right_distrib_class α] (n : α) : 2 * n = n + n
eq.trans (right_distrib 1 1 n) (by simp)
theorem
two_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "right_distrib", "right_distrib_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bit0_eq_two_mul [right_distrib_class α] (n : α) : bit0 n = 2 * n
(two_mul _).symm
theorem
bit0_eq_two_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "right_distrib_class", "two_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_two [left_distrib_class α] (n : α) : n * 2 = n + n
(left_distrib n 1 1).trans (by simp)
theorem
mul_two
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "left_distrib", "left_distrib_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_ite {α} [has_mul α] (P : Prop) [decidable P] (a b c : α) : a * (if P then b else c) = if P then a * b else a * c
by split_ifs; refl
lemma
mul_ite
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ite_mul {α} [has_mul α] (P : Prop) [decidable P] (a b c : α) : (if P then a else b) * c = if P then a * c else b * c
by split_ifs; refl
lemma
ite_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_boole {α} [mul_zero_one_class α] (P : Prop) [decidable P] (a : α) : a * (if P then 1 else 0) = if P then a else 0
by simp
lemma
mul_boole
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "mul_zero_one_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
boole_mul {α} [mul_zero_one_class α] (P : Prop) [decidable P] (a : α) : (if P then 1 else 0) * a = if P then a else 0
by simp
lemma
boole_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "mul_zero_one_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ite_mul_zero_left {α : Type*} [mul_zero_class α] (P : Prop) [decidable P] (a b : α) : ite P (a * b) 0 = ite P a 0 * b
by { by_cases h : P; simp [h], }
lemma
ite_mul_zero_left
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "mul_zero_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ite_mul_zero_right {α : Type*} [mul_zero_class α] (P : Prop) [decidable P] (a b : α) : ite P (a * b) 0 = a * ite P b 0
by { by_cases h : P; simp [h], }
lemma
ite_mul_zero_right
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "mul_zero_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ite_and_mul_zero {α : Type*} [mul_zero_class α] (P Q : Prop) [decidable P] [decidable Q] (a b : α) : ite (P ∧ Q) (a * b) 0 = ite P a 0 * ite Q b 0
by simp only [←ite_and, ite_mul, mul_ite, mul_zero, zero_mul, and_comm]
lemma
ite_and_mul_zero
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "ite_mul", "mul_ite", "mul_zero", "mul_zero_class", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
non_unital_comm_semiring (α : Type u) extends non_unital_semiring α, comm_semigroup α
class
non_unital_comm_semiring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "comm_semigroup", "non_unital_semiring" ]
A non-unital commutative semiring is a `non_unital_semiring` with commutative multiplication. In other words, it is a type with the following structures: additive commutative monoid (`add_comm_monoid`), commutative semigroup (`comm_semigroup`), distributive laws (`distrib`), and multiplication by zero law (`mul_zero_cl...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comm_semiring (α : Type u) extends semiring α, comm_monoid α
class
comm_semiring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "comm_monoid", "semiring" ]
A commutative semiring is a `semiring` with commutative multiplication. In other words, it is a type with the following structures: additive commutative monoid (`add_comm_monoid`), multiplicative commutative monoid (`comm_monoid`), distributive laws (`distrib`), and multiplication by zero law (`mul_zero_class`).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comm_semiring.to_non_unital_comm_semiring [comm_semiring α] : non_unital_comm_semiring α
{ .. comm_semiring.to_comm_monoid α, .. comm_semiring.to_semiring α }
instance
comm_semiring.to_non_unital_comm_semiring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "comm_semiring", "non_unital_comm_semiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comm_semiring.to_comm_monoid_with_zero [comm_semiring α] : comm_monoid_with_zero α
{ .. comm_semiring.to_comm_monoid α, .. comm_semiring.to_semiring α }
instance
comm_semiring.to_comm_monoid_with_zero
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "comm_monoid_with_zero", "comm_semiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_mul_self_eq (a b : α) : (a + b) * (a + b) = a*a + 2*a*b + b*b
by simp only [two_mul, add_mul, mul_add, add_assoc, mul_comm b]
lemma
add_mul_self_eq
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "mul_comm", "two_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
has_distrib_neg (α : Type*) [has_mul α] extends has_involutive_neg α
(neg_mul : ∀ x y : α, -x * y = -(x * y)) (mul_neg : ∀ x y : α, x * -y = -(x * y))
class
has_distrib_neg
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "has_involutive_neg", "mul_neg", "neg_mul" ]
Typeclass for a negation operator that distributes across multiplication. This is useful for dealing with submonoids of a ring that contain `-1` without having to duplicate lemmas.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_mul (a b : α) : - a * b = - (a * b)
has_distrib_neg.neg_mul _ _
lemma
neg_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_neg (a b : α) : a * - b = - (a * b)
has_distrib_neg.mul_neg _ _
lemma
mul_neg
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_mul_neg (a b : α) : -a * -b = a * b
by simp
lemma
neg_mul_neg
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_mul_eq_neg_mul (a b : α) : -(a * b) = -a * b
(neg_mul _ _).symm
lemma
neg_mul_eq_neg_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "neg_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_mul_eq_mul_neg (a b : α) : -(a * b) = a * -b
(mul_neg _ _).symm
lemma
neg_mul_eq_mul_neg
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "mul_neg" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_mul_comm (a b : α) : -a * b = a * -b
by simp
lemma
neg_mul_comm
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_eq_neg_one_mul (a : α) : -a = -1 * a
by simp
theorem
neg_eq_neg_one_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_neg_one (a : α) : a * -1 = -a
by simp
lemma
mul_neg_one
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
An element of a ring multiplied by the additive inverse of one is the element's additive inverse.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
neg_one_mul (a : α) : -1 * a = -a
by simp
lemma
neg_one_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
The additive inverse of one multiplied by an element of a ring is the element's additive inverse.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_zero_class.neg_zero_class : neg_zero_class α
{ neg_zero := by rw [←zero_mul (0 : α), ←neg_mul, mul_zero, mul_zero], ..mul_zero_class.to_has_zero α, ..has_distrib_neg.to_has_involutive_neg α }
instance
mul_zero_class.neg_zero_class
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "mul_zero", "neg_zero_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
non_unital_non_assoc_ring (α : Type u) extends add_comm_group α, non_unital_non_assoc_semiring α
class
non_unital_non_assoc_ring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "add_comm_group", "non_unital_non_assoc_semiring" ]
A not-necessarily-unital, not-necessarily-associative ring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
non_unital_ring (α : Type*) extends non_unital_non_assoc_ring α, non_unital_semiring α
class
non_unital_ring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "non_unital_non_assoc_ring", "non_unital_semiring" ]
An associative but not-necessarily unital ring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
non_assoc_ring (α : Type*) extends non_unital_non_assoc_ring α, non_assoc_semiring α, add_comm_group_with_one α
class
non_assoc_ring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "add_comm_group_with_one", "non_assoc_semiring", "non_unital_non_assoc_ring" ]
A unital but not-necessarily-associative ring.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ring (α : Type u) extends add_comm_group_with_one α, monoid α, distrib α
class
ring
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "add_comm_group_with_one", "distrib", "monoid" ]
A ring is a type with the following structures: additive commutative group (`add_comm_group`), multiplicative monoid (`monoid`), and distributive laws (`distrib`). Equivalently, a ring is a `semiring` with a negation operation making it an additive group.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
non_unital_non_assoc_ring.to_has_distrib_neg : has_distrib_neg α
{ neg := has_neg.neg, neg_neg := neg_neg, neg_mul := λ a b, eq_neg_of_add_eq_zero_left $ by rw [←right_distrib, add_left_neg, zero_mul], mul_neg := λ a b, eq_neg_of_add_eq_zero_left $ by rw [←left_distrib, add_left_neg, mul_zero] }
instance
non_unital_non_assoc_ring.to_has_distrib_neg
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "has_distrib_neg", "mul_neg", "mul_zero", "neg_mul", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_sub_left_distrib (a b c : α) : a * (b - c) = a * b - a * c
by simpa only [sub_eq_add_neg, neg_mul_eq_mul_neg] using mul_add a b (-c)
lemma
mul_sub_left_distrib
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "neg_mul_eq_mul_neg" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_sub_right_distrib (a b c : α) : (a - b) * c = a * c - b * c
by simpa only [sub_eq_add_neg, neg_mul_eq_neg_mul] using add_mul a (-b) c
lemma
mul_sub_right_distrib
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "neg_mul_eq_neg_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_add_eq_mul_add_iff_sub_mul_add_eq : a * e + c = b * e + d ↔ (a - b) * e + c = d
calc a * e + c = b * e + d ↔ a * e + c = d + b * e : by simp [add_comm] ... ↔ a * e + c - b * e = d : iff.intro (λ h, begin rw h, simp end) (λ h, begin rw ← h, simp end) ... ↔ (a - b) * e + c = d : begin simp [sub_mul, sub_add_eq_add_sub] end
theorem
mul_add_eq_mul_add_iff_sub_mul_add_eq
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
An iff statement following from right distributivity in rings and the definition of subtraction.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sub_mul_add_eq_of_mul_add_eq_mul_add : a * e + c = b * e + d → (a - b) * e + c = d
assume h, calc (a - b) * e + c = (a * e + c) - b * e : begin simp [sub_mul, sub_add_eq_add_sub] end ... = d : begin rw h, simp [@add_sub_cancel α] end
theorem
sub_mul_add_eq_of_mul_add_eq_mul_add
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[]
A simplification of one side of an equation exploiting right distributivity in rings and the definition of subtraction.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sub_one_mul (a b : α) : (a - 1) * b = a * b - b
by rw [sub_mul, one_mul]
lemma
sub_one_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "one_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_sub_one (a b : α) : a * (b - 1) = a * b - a
by rw [mul_sub, mul_one]
lemma
mul_sub_one
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "mul_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_sub_mul (a b : α) : (1 - a) * b = b - a * b
by rw [sub_mul, one_mul]
lemma
one_sub_mul
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "one_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_one_sub (a b : α) : a * (1 - b) = a - a * b
by rw [mul_sub, mul_one]
lemma
mul_one_sub
algebra.ring
src/algebra/ring/defs.lean
[ "algebra.group.basic", "algebra.group_with_zero.defs", "data.int.cast.defs" ]
[ "mul_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83