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radical_is_radical : (radical I).is_radical
λ r ⟨n, k, hrnki⟩, ⟨n * k, (pow_mul r n k).symm ▸ hrnki⟩
theorem
ideal.radical_is_radical
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "is_radical", "pow_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
radical_idem : radical (radical I) = radical I
(radical_is_radical I).radical
theorem
ideal.radical_idem
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_radical.radical_le_iff (hJ : J.is_radical) : radical I ≤ J ↔ I ≤ J
⟨le_trans le_radical, λ h, hJ.radical ▸ radical_mono h⟩
theorem
ideal.is_radical.radical_le_iff
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
radical_le_radical_iff : radical I ≤ radical J ↔ I ≤ radical J
(radical_is_radical J).radical_le_iff
theorem
ideal.radical_le_radical_iff
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
radical_eq_top : radical I = ⊤ ↔ I = ⊤
⟨λ h, (eq_top_iff_one _).2 $ let ⟨n, hn⟩ := (eq_top_iff_one _).1 h in @one_pow R _ n ▸ hn, λ h, h.symm ▸ radical_top R⟩
theorem
ideal.radical_eq_top
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "one_pow" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.is_radical (H : is_prime I) : I.is_radical
λ r ⟨n, hrni⟩, H.mem_of_pow_mem n hrni
theorem
ideal.is_prime.is_radical
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.radical (H : is_prime I) : radical I = I
H.is_radical.radical
theorem
ideal.is_prime.radical
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
radical_sup : radical (I ⊔ J) = radical (radical I ⊔ radical J)
le_antisymm (radical_mono $ sup_le_sup le_radical le_radical) $ radical_le_radical_iff.2 $ sup_le (radical_mono le_sup_left) (radical_mono le_sup_right)
theorem
ideal.radical_sup
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "le_sup_left", "le_sup_right", "sup_le", "sup_le_sup" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
radical_inf : radical (I ⊓ J) = radical I ⊓ radical J
le_antisymm (le_inf (radical_mono inf_le_left) (radical_mono inf_le_right)) (λ r ⟨⟨m, hrm⟩, ⟨n, hrn⟩⟩, ⟨m + n, (pow_add r m n).symm ▸ I.mul_mem_right _ hrm, (pow_add r m n).symm ▸ J.mul_mem_left _ hrn⟩)
theorem
ideal.radical_inf
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "inf_le_left", "inf_le_right", "le_inf", "pow_add" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
radical_mul : radical (I * J) = radical I ⊓ radical J
le_antisymm (radical_inf I J ▸ radical_mono $ @mul_le_inf _ _ I J) (λ r ⟨⟨m, hrm⟩, ⟨n, hrn⟩⟩, ⟨m + n, (pow_add r m n).symm ▸ mul_mem_mul hrm hrn⟩)
theorem
ideal.radical_mul
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "pow_add" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.radical_le_iff (hJ : is_prime J) : radical I ≤ J ↔ I ≤ J
hJ.is_radical.radical_le_iff
theorem
ideal.is_prime.radical_le_iff
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
radical_eq_Inf (I : ideal R) : radical I = Inf { J : ideal R | I ≤ J ∧ is_prime J }
le_antisymm (le_Inf $ λ J hJ, hJ.2.radical_le_iff.2 hJ.1) $ λ r hr, classical.by_contradiction $ λ hri, let ⟨m, (hrm : r ∉ radical m), him, hm⟩ := zorn_nonempty_partial_order₀ {K : ideal R | r ∉ radical K} (λ c hc hcc y hyc, ⟨Sup c, λ ⟨n, hrnc⟩, let ⟨y, hyc, hrny⟩ := (submodule.mem_Sup_of_directed ⟨y, hyc⟩ hc...
theorem
ideal.radical_eq_Inf
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "Inf_le", "ideal", "le_Inf", "le_sup_left", "le_sup_right", "mul_assoc", "mul_left_comm", "pow_add", "set.mem_singleton", "submodule.mem_Sup_of_directed", "zorn_nonempty_partial_order₀" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_radical_bot_of_no_zero_divisors {R} [comm_semiring R] [no_zero_divisors R] : (⊥ : ideal R).is_radical
λ x hx, hx.rec_on (λ n hn, pow_eq_zero hn)
lemma
ideal.is_radical_bot_of_no_zero_divisors
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "comm_semiring", "ideal", "is_radical", "no_zero_divisors", "pow_eq_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
radical_bot_of_no_zero_divisors {R : Type u} [comm_semiring R] [no_zero_divisors R] : radical (⊥ : ideal R) = ⊥
eq_bot_iff.2 is_radical_bot_of_no_zero_divisors
lemma
ideal.radical_bot_of_no_zero_divisors
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "comm_semiring", "ideal", "no_zero_divisors" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
top_pow (n : ℕ) : (⊤ ^ n : ideal R) = ⊤
nat.rec_on n one_eq_top $ λ n ih, by rw [pow_succ, ih, top_mul]
theorem
ideal.top_pow
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "ih", "pow_succ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
radical_pow (n : ℕ) (H : n > 0) : radical (I^n) = radical I
nat.rec_on n (not.elim dec_trivial) (λ n ih H, or.cases_on (lt_or_eq_of_le $ nat.le_of_lt_succ H) (λ H, calc radical (I^(n+1)) = radical I ⊓ radical (I^n) : by { rw pow_succ, exact radical_mul _ _ } ... = radical I ⊓ radical I : by rw ih H ... = radical I : inf_idem) (λ H, H ▸ (pow_one I).s...
theorem
ideal.radical_pow
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ih", "inf_idem", "not.elim", "pow_one", "pow_succ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.mul_le {I J P : ideal R} (hp : is_prime P) : I * J ≤ P ↔ I ≤ P ∨ J ≤ P
⟨λ h, or_iff_not_imp_left.2 $ λ hip j hj, let ⟨i, hi, hip⟩ := set.not_subset.1 hip in (hp.mem_or_mem $ h $ mul_mem_mul hi hj).resolve_left hip, λ h, or.cases_on h (le_trans $ le_trans mul_le_inf inf_le_left) (le_trans $ le_trans mul_le_inf inf_le_right)⟩
theorem
ideal.is_prime.mul_le
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "inf_le_left", "inf_le_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.inf_le {I J P : ideal R} (hp : is_prime P) : I ⊓ J ≤ P ↔ I ≤ P ∨ J ≤ P
⟨λ h, hp.mul_le.1 $ le_trans mul_le_inf h, λ h, or.cases_on h (le_trans inf_le_left) (le_trans inf_le_right)⟩
theorem
ideal.is_prime.inf_le
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "inf_le_left", "inf_le_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.multiset_prod_le {s : multiset (ideal R)} {P : ideal R} (hp : is_prime P) (hne : s ≠ 0) : s.prod ≤ P ↔ ∃ I ∈ s, I ≤ P
suffices s.prod ≤ P → ∃ I ∈ s, I ≤ P, from ⟨this, λ ⟨i, his, hip⟩, le_trans multiset_prod_le_inf $ le_trans (multiset.inf_le his) hip⟩, begin classical, obtain ⟨b, hb⟩ : ∃ b, b ∈ s := multiset.exists_mem_of_ne_zero hne, obtain ⟨t, rfl⟩ : ∃ t, s = b ::ₘ t, from ⟨s.erase b, (multiset.cons_erase hb).symm⟩, ...
theorem
ideal.is_prime.multiset_prod_le
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "exists_eq_left", "exists_prop", "ideal", "ih", "imp_self", "multiset", "multiset.cons_erase", "multiset.cons_swap", "multiset.cons_zero", "multiset.exists_mem_of_ne_zero", "multiset.inf_le", "multiset.mem_cons_of_mem", "multiset.mem_cons_self", "multiset.mem_singleton", "multiset.prod_c...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.multiset_prod_map_le {s : multiset ι} (f : ι → ideal R) {P : ideal R} (hp : is_prime P) (hne : s ≠ 0) : (s.map f).prod ≤ P ↔ ∃ i ∈ s, f i ≤ P
begin rw hp.multiset_prod_le (mt multiset.map_eq_zero.mp hne), simp_rw [exists_prop, multiset.mem_map, exists_exists_and_eq_and], end
theorem
ideal.is_prime.multiset_prod_map_le
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "exists_exists_and_eq_and", "exists_prop", "ideal", "multiset", "multiset.mem_map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.prod_le {s : finset ι} {f : ι → ideal R} {P : ideal R} (hp : is_prime P) (hne : s.nonempty) : s.prod f ≤ P ↔ ∃ i ∈ s, f i ≤ P
hp.multiset_prod_map_le f (mt finset.val_eq_zero.mp hne.ne_empty)
theorem
ideal.is_prime.prod_le
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "finset", "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.inf_le' {s : finset ι} {f : ι → ideal R} {P : ideal R} (hp : is_prime P) (hsne: s.nonempty) : s.inf f ≤ P ↔ ∃ i ∈ s, f i ≤ P
⟨λ h, (hp.prod_le hsne).1 $ le_trans prod_le_inf h, λ ⟨i, his, hip⟩, le_trans (finset.inf_le his) hip⟩
theorem
ideal.is_prime.inf_le'
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "finset", "finset.inf_le", "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subset_union {R : Type u} [ring R] {I J K : ideal R} : (I : set R) ⊆ J ∪ K ↔ I ≤ J ∨ I ≤ K
⟨λ h, or_iff_not_imp_left.2 $ λ hij s hsi, let ⟨r, hri, hrj⟩ := set.not_subset.1 hij in classical.by_contradiction $ λ hsk, or.cases_on (h $ I.add_mem hri hsi) (λ hj, hrj $ add_sub_cancel r s ▸ J.sub_mem hj ((h hsi).resolve_right hsk)) (λ hk, hsk $ add_sub_cancel' r s ▸ K.sub_mem hk ((h hri).resolve_left hr...
theorem
ideal.subset_union
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "ring", "set.subset.trans", "set.subset_union_left", "set.subset_union_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subset_union_prime' {R : Type u} [comm_ring R] {s : finset ι} {f : ι → ideal R} {a b : ι} (hp : ∀ i ∈ s, is_prime (f i)) {I : ideal R} : (I : set R) ⊆ f a ∪ f b ∪ (⋃ i ∈ (↑s : set ι), f i) ↔ I ≤ f a ∨ I ≤ f b ∨ ∃ i ∈ s, I ≤ f i
suffices (I : set R) ⊆ f a ∪ f b ∪ (⋃ i ∈ (↑s : set ι), f i) → I ≤ f a ∨ I ≤ f b ∨ ∃ i ∈ s, I ≤ f i, from ⟨this, λ h, or.cases_on h (λ h, set.subset.trans h $ set.subset.trans (set.subset_union_left _ _) (set.subset_union_left _ _)) $ λ h, or.cases_on h (λ h, set.subset.trans h $ set.subset.trans (s...
theorem
ideal.subset_union_prime'
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "comm_ring", "exists_false", "exists_prop", "finset", "finset.card_eq_zero", "finset.card_insert_of_not_mem", "finset.coe_empty", "finset.coe_insert", "finset.forall_mem_insert", "finset.inf_empty", "finset.inf_eq_infi", "finset.insert_erase", "finset.insert_subset_insert", "finset.mem_ins...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
subset_union_prime {R : Type u} [comm_ring R] {s : finset ι} {f : ι → ideal R} (a b : ι) (hp : ∀ i ∈ s, i ≠ a → i ≠ b → is_prime (f i)) {I : ideal R} : (I : set R) ⊆ (⋃ i ∈ (↑s : set ι), f i) ↔ ∃ i ∈ s, I ≤ f i
suffices (I : set R) ⊆ (⋃ i ∈ (↑s : set ι), f i) → ∃ i, i ∈ s ∧ I ≤ f i, from ⟨λ h, bex_def.2 $ this h, λ ⟨i, his, hi⟩, set.subset.trans hi $ set.subset_bUnion_of_mem $ show i ∈ (↑s : set ι), from his⟩, assume h : (I : set R) ⊆ (⋃ i ∈ (↑s : set ι), f i), begin classical, by_cases has : a ∈ s, { unfreezingI ...
theorem
ideal.subset_union_prime
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "bex_def", "comm_ring", "finset", "finset.coe_empty", "finset.coe_insert", "finset.exists_mem_insert", "finset.insert_erase", "finset.mem_insert_of_mem", "finset.not_mem_erase", "ideal", "set.bUnion_empty", "set.bUnion_insert", "set.nonempty_of_mem", "set.subset.trans", "set.subset_bUnio...
Prime avoidance. Atiyah-Macdonald 1.11, Eisenbud 3.3, Stacks 00DS, Matsumura Ex.1.6.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_of_dvd {I J : ideal R} : I ∣ J → J ≤ I
| ⟨K, h⟩ := h.symm ▸ le_trans mul_le_inf inf_le_left
lemma
ideal.le_of_dvd
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "inf_le_left" ]
If `I` divides `J`, then `I` contains `J`. In a Dedekind domain, to divide and contain are equivalent, see `ideal.dvd_iff_le`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_unit_iff {I : ideal R} : is_unit I ↔ I = ⊤
is_unit_iff_dvd_one.trans ((@one_eq_top R _).symm ▸ ⟨λ h, eq_top_iff.mpr (ideal.le_of_dvd h), λ h, ⟨⊤, by rw [mul_top, h]⟩⟩)
lemma
ideal.is_unit_iff
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "ideal.le_of_dvd", "is_unit" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
unique_units : unique ((ideal R)ˣ)
{ default := 1, uniq := λ u, units.ext (show (u : ideal R) = 1, by rw [is_unit_iff.mp u.is_unit, one_eq_top]) }
instance
ideal.unique_units
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "unique", "units.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map (I : ideal R) : ideal S
span (f '' I)
def
ideal.map
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
`I.map f` is the span of the image of the ideal `I` under `f`, which may be bigger than the image itself.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap (I : ideal S) : ideal R
{ carrier := f ⁻¹' I, add_mem' := λ x y hx hy, by simp only [set.mem_preimage, set_like.mem_coe, map_add, add_mem hx hy] at *, zero_mem' := by simp only [set.mem_preimage, map_zero, set_like.mem_coe, submodule.zero_mem], smul_mem' := λ c x hx, by { simp only [smul_eq_mul, ...
def
ideal.comap
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "map_mul", "set.mem_preimage", "set_like.mem_coe", "smul_eq_mul", "submodule.zero_mem" ]
`I.comap f` is the preimage of `I` under `f`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_mono (h : I ≤ J) : map f I ≤ map f J
span_mono $ set.image_subset _ h
theorem
ideal.map_mono
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "set.image_subset" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_map_of_mem (f : F) {I : ideal R} {x : R} (h : x ∈ I) : f x ∈ map f I
subset_span ⟨x, h, rfl⟩
theorem
ideal.mem_map_of_mem
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
apply_coe_mem_map (f : F) (I : ideal R) (x : I) : f x ∈ I.map f
mem_map_of_mem f x.prop
lemma
ideal.apply_coe_mem_map
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_le_iff_le_comap : map f I ≤ K ↔ I ≤ comap f K
span_le.trans set.image_subset_iff
theorem
ideal.map_le_iff_le_comap
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "set.image_subset_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_comap {x} : x ∈ comap f K ↔ f x ∈ K
iff.rfl
theorem
ideal.mem_comap
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_mono (h : K ≤ L) : comap f K ≤ comap f L
set.preimage_mono (λ x hx, h hx)
theorem
ideal.comap_mono
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "set.preimage_mono" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_ne_top (hK : K ≠ ⊤) : comap f K ≠ ⊤
(ne_top_iff_one _).2 $ by rw [mem_comap, map_one]; exact (ne_top_iff_one _).1 hK
theorem
ideal.comap_ne_top
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "map_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_le_comap_of_inv_on (g : G) (I : ideal R) (hf : set.left_inv_on g f I) : I.map f ≤ I.comap g
begin refine ideal.span_le.2 _, rintros x ⟨x, hx, rfl⟩, rw [set_like.mem_coe, mem_comap, hf hx], exact hx, end
lemma
ideal.map_le_comap_of_inv_on
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "set.left_inv_on", "set_like.mem_coe" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_le_map_of_inv_on (g : G) (I : ideal S) (hf : set.left_inv_on g f (f ⁻¹' I)) : I.comap f ≤ I.map g
λ x (hx : f x ∈ I), hf hx ▸ ideal.mem_map_of_mem g hx
lemma
ideal.comap_le_map_of_inv_on
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "ideal.mem_map_of_mem", "set.left_inv_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_le_comap_of_inverse (g : G) (I : ideal R) (h : function.left_inverse g f) : I.map f ≤ I.comap g
map_le_comap_of_inv_on _ _ _ $ h.left_inv_on _
lemma
ideal.map_le_comap_of_inverse
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
The `ideal` version of `set.image_subset_preimage_of_inverse`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_le_map_of_inverse (g : G) (I : ideal S) (h : function.left_inverse g f) : I.comap f ≤ I.map g
comap_le_map_of_inv_on _ _ _ $ h.left_inv_on _
lemma
ideal.comap_le_map_of_inverse
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
The `ideal` version of `set.preimage_subset_image_of_inverse`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_prime.comap [hK : K.is_prime] : (comap f K).is_prime
⟨comap_ne_top _ hK.1, λ x y, by simp only [mem_comap, map_mul]; apply hK.2⟩
instance
ideal.is_prime.comap
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "map_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_top : map f ⊤ = ⊤
(eq_top_iff_one _).2 $ subset_span ⟨1, trivial, map_one f⟩
theorem
ideal.map_top
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "map_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gc_map_comap : galois_connection (ideal.map f) (ideal.comap f)
λ I J, ideal.map_le_iff_le_comap
lemma
ideal.gc_map_comap
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_connection", "ideal.comap", "ideal.map", "ideal.map_le_iff_le_comap" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_id : I.comap (ring_hom.id R) = I
ideal.ext $ λ _, iff.rfl
lemma
ideal.comap_id
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal.ext", "ring_hom.id" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_id : I.map (ring_hom.id R) = I
(gc_map_comap (ring_hom.id R)).l_unique galois_connection.id comap_id
lemma
ideal.map_id
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_connection.id", "map_id", "ring_hom.id" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_comap {T : Type*} [semiring T] {I : ideal T} (f : R →+* S) (g : S →+* T) : (I.comap g).comap f = I.comap (g.comp f)
rfl
lemma
ideal.comap_comap
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "semiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_map {T : Type*} [semiring T] {I : ideal R} (f : R →+* S) (g : S →+* T) : (I.map f).map g = I.map (g.comp f)
((gc_map_comap f).compose (gc_map_comap g)).l_unique (gc_map_comap (g.comp f)) (λ _, comap_comap _ _)
lemma
ideal.map_map
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "semiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_span (f : F) (s : set R) : map f (span s) = span (f '' s)
symm $ submodule.span_eq_of_le _ (λ y ⟨x, hy, x_eq⟩, x_eq ▸ mem_map_of_mem f (subset_span hy)) (map_le_iff_le_comap.2 $ span_le.2 $ set.image_subset_iff.1 subset_span)
lemma
ideal.map_span
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "submodule.span_eq_of_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_le_of_le_comap : I ≤ K.comap f → I.map f ≤ K
(gc_map_comap f).l_le
lemma
ideal.map_le_of_le_comap
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_comap_of_map_le : I.map f ≤ K → I ≤ K.comap f
(gc_map_comap f).le_u
lemma
ideal.le_comap_of_map_le
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_comap_map : I ≤ (I.map f).comap f
(gc_map_comap f).le_u_l _
lemma
ideal.le_comap_map
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_comap_le : (K.comap f).map f ≤ K
(gc_map_comap f).l_u_le _
lemma
ideal.map_comap_le
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_top : (⊤ : ideal S).comap f = ⊤
(gc_map_comap f).u_top
lemma
ideal.comap_top
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_eq_top_iff {I : ideal S} : I.comap f = ⊤ ↔ I = ⊤
⟨ λ h, I.eq_top_iff_one.mpr (map_one f ▸ mem_comap.mp ((I.comap f).eq_top_iff_one.mp h)), λ h, by rw [h, comap_top] ⟩
lemma
ideal.comap_eq_top_iff
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "map_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_bot : (⊥ : ideal R).map f = ⊥
(gc_map_comap f).l_bot
lemma
ideal.map_bot
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_comap_map : ((I.map f).comap f).map f = I.map f
(gc_map_comap f).l_u_l_eq_l I
lemma
ideal.map_comap_map
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_map_comap : ((K.comap f).map f).comap f = K.comap f
(gc_map_comap f).u_l_u_eq_u K
lemma
ideal.comap_map_comap
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_sup : (I ⊔ J).map f = I.map f ⊔ J.map f
(gc_map_comap f : galois_connection (map f) (comap f)).l_sup
lemma
ideal.map_sup
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_connection" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_inf : comap f (K ⊓ L) = comap f K ⊓ comap f L
rfl
theorem
ideal.comap_inf
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_supr (K : ι → ideal R) : (supr K).map f = ⨆ i, (K i).map f
(gc_map_comap f : galois_connection (map f) (comap f)).l_supr
lemma
ideal.map_supr
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_connection", "ideal", "map_supr", "supr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_infi (K : ι → ideal S) : (infi K).comap f = ⨅ i, (K i).comap f
(gc_map_comap f : galois_connection (map f) (comap f)).u_infi
lemma
ideal.comap_infi
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_connection", "ideal", "infi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_Sup (s : set (ideal R)): (Sup s).map f = ⨆ I ∈ s, (I : ideal R).map f
(gc_map_comap f : galois_connection (map f) (comap f)).l_Sup
lemma
ideal.map_Sup
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_connection", "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_Inf (s : set (ideal S)): (Inf s).comap f = ⨅ I ∈ s, (I : ideal S).comap f
(gc_map_comap f : galois_connection (map f) (comap f)).u_Inf
lemma
ideal.comap_Inf
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_connection", "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_Inf' (s : set (ideal S)) : (Inf s).comap f = ⨅ I ∈ (comap f '' s), I
trans (comap_Inf f s) (by rw infi_image)
lemma
ideal.comap_Inf'
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "infi_image" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_is_prime [H : is_prime K] : is_prime (comap f K)
⟨comap_ne_top f H.ne_top, λ x y h, H.mem_or_mem $ by rwa [mem_comap, map_mul] at h⟩
theorem
ideal.comap_is_prime
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "map_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_inf_le : map f (I ⊓ J) ≤ map f I ⊓ map f J
(gc_map_comap f : galois_connection (map f) (comap f)).monotone_l.map_inf_le _ _
theorem
ideal.map_inf_le
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_connection" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_comap_sup : comap f K ⊔ comap f L ≤ comap f (K ⊔ L)
(gc_map_comap f : galois_connection (map f) (comap f)).monotone_u.le_map_sup _ _
theorem
ideal.le_comap_sup
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_connection" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_top_eq_map {R S : Type*} [comm_semiring R] [comm_semiring S] [algebra R S] (I : ideal R) : I • (⊤ : submodule R S) = (I.map (algebra_map R S)).restrict_scalars R
begin refine le_antisymm (submodule.smul_le.mpr (λ r hr y _, _) ) (λ x hx, submodule.span_induction hx _ _ _ _), { rw algebra.smul_def, exact mul_mem_right _ _ (mem_map_of_mem _ hr) }, { rintros _ ⟨x, hx, rfl⟩, rw [← mul_one (algebra_map R S x), ← algebra.smul_def], exact submodule.smul_mem_sm...
lemma
ideal.smul_top_eq_map
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "algebra", "algebra.smul_def", "algebra_map", "comm_semiring", "ideal", "mul_one", "restrict_scalars", "smul_add", "submodule", "submodule.add_mem", "submodule.mem_top", "submodule.smul_induction_on", "submodule.smul_mem_smul", "submodule.span_induction", "submodule.zero_mem" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
coe_restrict_scalars {R S : Type*} [comm_semiring R] [semiring S] [algebra R S] (I : ideal S) : ((I.restrict_scalars R) : set S) = ↑I
rfl
lemma
ideal.coe_restrict_scalars
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "algebra", "comm_semiring", "ideal", "semiring" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
restrict_scalars_mul {R S : Type*} [comm_semiring R] [comm_semiring S] [algebra R S] (I J : ideal S) : (I * J).restrict_scalars R = I.restrict_scalars R * J.restrict_scalars R
le_antisymm (λ x hx, submodule.mul_induction_on hx (λ x hx y hy, submodule.mul_mem_mul hx hy) (λ x y, submodule.add_mem _)) (submodule.mul_le.mpr (λ x hx y hy, ideal.mul_mem_mul hx hy))
lemma
ideal.restrict_scalars_mul
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "algebra", "comm_semiring", "ideal", "ideal.mul_mem_mul", "restrict_scalars", "submodule.add_mem", "submodule.mul_induction_on", "submodule.mul_mem_mul" ]
The smallest `S`-submodule that contains all `x ∈ I * y ∈ J` is also the smallest `R`-submodule that does so.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_comap_of_surjective (I : ideal S) : map f (comap f I) = I
le_antisymm (map_le_iff_le_comap.2 le_rfl) (λ s hsi, let ⟨r, hfrs⟩ := hf s in hfrs ▸ (mem_map_of_mem f $ show f r ∈ I, from hfrs.symm ▸ hsi))
theorem
ideal.map_comap_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "le_rfl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
gi_map_comap : galois_insertion (map f) (comap f)
galois_insertion.monotone_intro ((gc_map_comap f).monotone_u) ((gc_map_comap f).monotone_l) (λ _, le_comap_map) (map_comap_of_surjective _ hf)
def
ideal.gi_map_comap
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "galois_insertion", "galois_insertion.monotone_intro" ]
`map` and `comap` are adjoint, and the composition `map f ∘ comap f` is the identity
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_surjective_of_surjective : surjective (map f)
(gi_map_comap f hf).l_surjective
lemma
ideal.map_surjective_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_injective_of_surjective : injective (comap f)
(gi_map_comap f hf).u_injective
lemma
ideal.comap_injective_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_sup_comap_of_surjective (I J : ideal S) : (I.comap f ⊔ J.comap f).map f = I ⊔ J
(gi_map_comap f hf).l_sup_u _ _
lemma
ideal.map_sup_comap_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_supr_comap_of_surjective (K : ι → ideal S) : (⨆i, (K i).comap f).map f = supr K
(gi_map_comap f hf).l_supr_u _
lemma
ideal.map_supr_comap_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "supr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_inf_comap_of_surjective (I J : ideal S) : (I.comap f ⊓ J.comap f).map f = I ⊓ J
(gi_map_comap f hf).l_inf_u _ _
lemma
ideal.map_inf_comap_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_infi_comap_of_surjective (K : ι → ideal S) : (⨅i, (K i).comap f).map f = infi K
(gi_map_comap f hf).l_infi_u _
lemma
ideal.map_infi_comap_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "infi" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_image_of_mem_map_of_surjective {I : ideal R} {y} (H : y ∈ map f I) : y ∈ f '' I
submodule.span_induction H (λ _, id) ⟨0, I.zero_mem, map_zero f⟩ (λ y1 y2 ⟨x1, hx1i, hxy1⟩ ⟨x2, hx2i, hxy2⟩, ⟨x1 + x2, I.add_mem hx1i hx2i, hxy1 ▸ hxy2 ▸ map_add f _ _⟩) (λ c y ⟨x, hxi, hxy⟩, let ⟨d, hdc⟩ := hf c in ⟨d * x, I.mul_mem_left _ hxi, hdc ▸ hxy ▸ map_mul f _ _⟩)
theorem
ideal.mem_image_of_mem_map_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "map_mul", "submodule.span_induction" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_map_iff_of_surjective {I : ideal R} {y} : y ∈ map f I ↔ ∃ x, x ∈ I ∧ f x = y
⟨λ h, (set.mem_image _ _ _).2 (mem_image_of_mem_map_of_surjective f hf h), λ ⟨x, hx⟩, hx.right ▸ (mem_map_of_mem f hx.left)⟩
lemma
ideal.mem_map_iff_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "set.mem_image" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_map_of_comap_le_of_surjective : comap f K ≤ I → K ≤ map f I
λ h, (map_comap_of_surjective f hf K) ▸ map_mono h
lemma
ideal.le_map_of_comap_le_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_eq_submodule_map (f : R →+* S) [h : ring_hom_surjective f] (I : ideal R) : I.map f = submodule.map f.to_semilinear_map I
submodule.ext (λ x, mem_map_iff_of_surjective f h.1)
lemma
ideal.map_eq_submodule_map
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "ring_hom_surjective", "submodule.ext", "submodule.map" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_bot_le_of_injective : comap f ⊥ ≤ I
begin refine le_trans (λ x hx, _) bot_le, rw [mem_comap, submodule.mem_bot, ← map_zero f] at hx, exact eq.symm (hf hx) ▸ (submodule.zero_mem ⊥) end
lemma
ideal.comap_bot_le_of_injective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "bot_le", "submodule.mem_bot", "submodule.zero_mem" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_bot_of_injective : ideal.comap f ⊥ = ⊥
le_bot_iff.mp (ideal.comap_bot_le_of_injective f hf)
lemma
ideal.comap_bot_of_injective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal.comap", "ideal.comap_bot_le_of_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_map_of_surjective (I : ideal R) : comap f (map f I) = I ⊔ comap f ⊥
le_antisymm (assume r h, let ⟨s, hsi, hfsr⟩ := mem_image_of_mem_map_of_surjective f hf h in submodule.mem_sup.2 ⟨s, hsi, r - s, (submodule.mem_bot S).2 $ by rw [map_sub, hfsr, sub_self], add_sub_cancel'_right s r⟩) (sup_le (map_le_iff_le_comap.1 le_rfl) (comap_mono bot_le))
theorem
ideal.comap_map_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "bot_le", "ideal", "le_rfl", "submodule.mem_bot", "sup_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rel_iso_of_surjective : ideal S ≃o { p : ideal R // comap f ⊥ ≤ p }
{ to_fun := λ J, ⟨comap f J, comap_mono bot_le⟩, inv_fun := λ I, map f I.1, left_inv := λ J, map_comap_of_surjective f hf J, right_inv := λ I, subtype.eq $ show comap f (map f I.1) = I.1, from (comap_map_of_surjective f hf I).symm ▸ le_antisymm (sup_le le_rfl I.2) le_sup_left, map_rel_iff' := λ I1 I2,...
def
ideal.rel_iso_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "inv_fun", "le_rfl", "le_sup_left", "sup_le" ]
Correspondence theorem
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
order_embedding_of_surjective : ideal S ↪o ideal R
(rel_iso_of_surjective f hf).to_rel_embedding.trans (subtype.rel_embedding _ _)
def
ideal.order_embedding_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "subtype.rel_embedding" ]
The map on ideals induced by a surjective map preserves inclusion.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_eq_top_or_is_maximal_of_surjective {I : ideal R} (H : is_maximal I) : (map f I) = ⊤ ∨ is_maximal (map f I)
begin refine or_iff_not_imp_left.2 (λ ne_top, ⟨⟨λ h, ne_top h, λ J hJ, _⟩⟩), { refine (rel_iso_of_surjective f hf).injective (subtype.ext_iff.2 (eq.trans (H.1.2 (comap f J) (lt_of_le_of_ne _ _)) comap_top.symm)), { exact (map_le_iff_le_comap).1 (le_of_lt hJ) }, { exact λ h, hJ.right (le_map_of_comap_l...
theorem
ideal.map_eq_top_or_is_maximal_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_is_maximal_of_surjective {K : ideal S} [H : is_maximal K] : is_maximal (comap f K)
begin refine ⟨⟨comap_ne_top _ H.1.1, λ J hJ, _⟩⟩, suffices : map f J = ⊤, { replace this := congr_arg (comap f) this, rw [comap_top, comap_map_of_surjective _ hf, eq_top_iff] at this, rw eq_top_iff, exact le_trans this (sup_le (le_of_eq rfl) (le_trans (comap_mono (bot_le)) (le_of_lt hJ))) }, refine ...
theorem
ideal.comap_is_maximal_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "bot_le", "eq_top_iff", "ideal", "sup_eq_left", "sup_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_le_comap_iff_of_surjective (I J : ideal S) : comap f I ≤ comap f J ↔ I ≤ J
⟨λ h, (map_comap_of_surjective f hf I).symm.le.trans (map_le_of_le_comap h), λ h, le_comap_of_map_le ((map_comap_of_surjective f hf I).le.trans h)⟩
theorem
ideal.comap_le_comap_iff_of_surjective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_of_equiv (I : ideal R) (f : R ≃+* S) : (I.map (f : R →+* S)).map (f.symm : S →+* R) = I
by simp [← ring_equiv.to_ring_hom_eq_coe, map_map]
lemma
ideal.map_of_equiv
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "ring_equiv.to_ring_hom_eq_coe" ]
If `f : R ≃+* S` is a ring isomorphism and `I : ideal R`, then `map f (map f.symm) = I`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_of_equiv (I : ideal R) (f : R ≃+* S) : (I.comap (f.symm : S →+* R)).comap (f : R →+* S) = I
by simp [← ring_equiv.to_ring_hom_eq_coe, comap_comap]
lemma
ideal.comap_of_equiv
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "ring_equiv.to_ring_hom_eq_coe" ]
If `f : R ≃+* S` is a ring isomorphism and `I : ideal R`, then `comap f.symm (comap f) = I`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_comap_of_equiv (I : ideal R) (f : R ≃+* S) : I.map (f : R →+* S) = I.comap f.symm
le_antisymm (le_comap_of_map_le (map_of_equiv I f).le) (le_map_of_comap_le_of_surjective _ f.surjective (comap_of_equiv I f).le)
lemma
ideal.map_comap_of_equiv
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
If `f : R ≃+* S` is a ring isomorphism and `I : ideal R`, then `map f I = comap f.symm I`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rel_iso_of_bijective : ideal S ≃o ideal R
{ to_fun := comap f, inv_fun := map f, left_inv := (rel_iso_of_surjective f hf.right).left_inv, right_inv := λ J, subtype.ext_iff.1 ((rel_iso_of_surjective f hf.right).right_inv ⟨J, comap_bot_le_of_injective f hf.left⟩), map_rel_iff' := λ _ _, (rel_iso_of_surjective f hf.right).map_rel_iff' }
def
ideal.rel_iso_of_bijective
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "inv_fun" ]
Special case of the correspondence theorem for isomorphic rings
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comap_le_iff_le_map {I : ideal R} {K : ideal S} : comap f K ≤ I ↔ K ≤ map f I
⟨λ h, le_map_of_comap_le_of_surjective f hf.right h, λ h, ((rel_iso_of_bijective f hf).right_inv I) ▸ comap_mono h⟩
lemma
ideal.comap_le_iff_le_map
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map.is_maximal {I : ideal R} (H : is_maximal I) : is_maximal (map f I)
by refine or_iff_not_imp_left.1 (map_eq_top_or_is_maximal_of_surjective f hf.right H) (λ h, H.1.1 _); calc I = comap f (map f I) : ((rel_iso_of_bijective f hf).right_inv I).symm ... = comap f ⊤ : by rw h ... = ⊤ : by rw comap_top
theorem
ideal.map.is_maximal
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ring_equiv.bot_maximal_iff (e : R ≃+* S) : (⊥ : ideal R).is_maximal ↔ (⊥ : ideal S).is_maximal
⟨λ h, (@map_bot _ _ _ _ _ _ e.to_ring_hom) ▸ map.is_maximal e.to_ring_hom e.bijective h, λ h, (@map_bot _ _ _ _ _ _ e.symm.to_ring_hom) ▸ map.is_maximal e.symm.to_ring_hom e.symm.bijective h⟩
lemma
ideal.ring_equiv.bot_maximal_iff
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_mul : map f (I * J) = map f I * map f J
le_antisymm (map_le_iff_le_comap.2 $ mul_le.2 $ λ r hri s hsj, show f (r * s) ∈ _, by rw map_mul; exact mul_mem_mul (mem_map_of_mem f hri) (mem_map_of_mem f hsj)) (trans_rel_right _ (span_mul_span _ _) $ span_le.2 $ set.Union₂_subset $ λ i ⟨r, hri, hfri⟩, set.Union₂_subset $ λ j ⟨s, hsj, hfsj⟩, set.singleton_...
theorem
ideal.map_mul
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "map_mul", "set.Union₂_subset" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
map_hom : ideal R →*₀ ideal S
{ to_fun := map f, map_mul' := λ I J, ideal.map_mul f I J, map_one' := by convert ideal.map_top f; exact one_eq_top, map_zero' := ideal.map_bot }
def
ideal.map_hom
ring_theory.ideal
src/ring_theory/ideal/operations.lean
[ "algebra.algebra.operations", "algebra.ring.equiv", "data.nat.choose.sum", "linear_algebra.basis.bilinear", "ring_theory.coprime.lemmas", "ring_theory.ideal.basic", "ring_theory.non_zero_divisors" ]
[ "ideal", "ideal.map_bot", "ideal.map_mul", "ideal.map_top" ]
The pushforward `ideal.map` as a monoid-with-zero homomorphism.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83