-
-
Save PatrickMassot/9c5246efe8d1fd4f26c21cbf2ac99ff8 to your computer and use it in GitHub Desktop.
Failed transport of structure
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import data.equiv.basic | |
import algebra.ring | |
variables {α : Type*} {β : Type*} (e : α ≃ β) | |
include e | |
@[to_additive has_zero_of_equiv] | |
def has_one_of_equiv [has_one α] : has_one β := ⟨e 1⟩ | |
@[to_additive has_add_of_equiv] | |
def has_mul_of_equiv [has_mul α] : has_mul β := ⟨λ x y, e $ (e.symm x) * (e.symm y)⟩ | |
@[to_additive has_neg_of_equiv] | |
def has_inv_of_equiv [has_inv α] : has_inv β := ⟨λ x, e $ (e.symm x)⁻¹⟩ | |
def monoid_of_equiv [monoid α] : monoid β := | |
begin | |
refine_struct {..has_one_of_equiv e, ..has_mul_of_equiv e}, | |
{ intros a b c, | |
dsimp [has_mul_of_equiv], | |
simp [mul_assoc] }, | |
{ intro a, | |
change e (e.symm (e 1) * e.symm a) = a, | |
simp }, | |
{ intro a, | |
change e (e.symm a * e.symm (e 1)) = a, | |
simp } | |
end | |
attribute [to_additive add_monoid_of_equiv._proof_1] monoid_of_equiv._proof_1 | |
attribute [to_additive add_monoid_of_equiv._proof_2] monoid_of_equiv._proof_2 | |
attribute [to_additive add_monoid_of_equiv._proof_3] monoid_of_equiv._proof_3 | |
attribute [to_additive add_monoid_of_equiv] monoid_of_equiv | |
attribute [to_additive add_monoid_of_equiv.equations._eqn_1] monoid_of_equiv.equations._eqn_1 | |
@[to_additive of_equiv_add_monoid_hom] | |
lemma of_equiv_monoid_hom [monoid α] : @is_monoid_hom α β _ (monoid_of_equiv e) e := | |
{ map_one := rfl, | |
map_mul := λ x y, by change e (x * y) = e(e.symm (e x) * e.symm(e y)); simp } | |
def comm_monoid_of_equiv [comm_monoid α] : comm_monoid β := | |
begin | |
refine_struct {..monoid_of_equiv e}, | |
{ intros a b, | |
change e (e.symm a * e.symm b) = e (e.symm b * e.symm a), | |
rw mul_comm }, | |
end | |
attribute [to_additive add_comm_monoid_of_equiv._proof_1] comm_monoid_of_equiv._proof_1 | |
attribute [to_additive add_comm_monoid_of_equiv._proof_2] comm_monoid_of_equiv._proof_2 | |
attribute [to_additive add_comm_monoid_of_equiv._proof_3] comm_monoid_of_equiv._proof_3 | |
attribute [to_additive add_comm_monoid_of_equiv._proof_4] comm_monoid_of_equiv._proof_4 | |
attribute [to_additive add_comm_monoid_of_equiv] comm_monoid_of_equiv | |
attribute [to_additive add_comm_monoid_of_equiv.equations._eqn_1] comm_monoid_of_equiv.equations._eqn_1 | |
def group_of_equiv [group α] : group β := | |
begin | |
refine_struct {..monoid_of_equiv e, ..has_inv_of_equiv e}, | |
intro a, | |
change e ( e.symm (e ((equiv.symm e) a)⁻¹) * (e.symm a)) = e 1, | |
simp, | |
end | |
attribute [to_additive add_group_of_equiv._proof_1] group_of_equiv._proof_1 | |
attribute [to_additive add_group_of_equiv._proof_2] group_of_equiv._proof_2 | |
attribute [to_additive add_group_of_equiv._proof_3] group_of_equiv._proof_3 | |
attribute [to_additive add_group_of_equiv._proof_4] group_of_equiv._proof_4 | |
attribute [to_additive add_group_of_equiv] group_of_equiv | |
attribute [to_additive add_group_of_equiv.equations._eqn_1] group_of_equiv.equations._eqn_1 | |
@[to_additive of_equiv_add_group_hom] | |
lemma of_equiv_group_hom [group α] : @is_group_hom α β _ (group_of_equiv e) e := | |
begin | |
constructor, | |
intros x y, | |
change e (x * y) = e(e.symm (e x) * e.symm(e y)), simp, | |
end | |
def comm_group_of_equiv [comm_group α] : comm_group β := | |
begin | |
-- I could add comm_monoid_of_equiv e but that seems to confuse `to_additive` | |
refine_struct {..group_of_equiv e}, | |
intros a b, | |
change e (e.symm a * e.symm b) = e (e.symm b * e.symm a), | |
rw mul_comm | |
end | |
attribute [to_additive add_comm_group_of_equiv._proof_1] comm_group_of_equiv._proof_1 | |
attribute [to_additive add_comm_group_of_equiv._proof_2] comm_group_of_equiv._proof_2 | |
attribute [to_additive add_comm_group_of_equiv._proof_3] comm_group_of_equiv._proof_3 | |
attribute [to_additive add_comm_group_of_equiv._proof_4] comm_group_of_equiv._proof_4 | |
attribute [to_additive add_comm_group_of_equiv._proof_5] comm_group_of_equiv._proof_5 | |
attribute [to_additive add_comm_group_of_equiv] comm_group_of_equiv | |
attribute [to_additive add_comm_group_of_equiv.equations._eqn_1] comm_group_of_equiv.equations._eqn_1 | |
def ring_of_equiv [ring α] : ring β := | |
begin | |
refine_struct {..add_comm_group_of_equiv e, ..monoid_of_equiv e}, | |
{ intros a b c, | |
haveI := add_comm_group_of_equiv e, | |
apply congr_arg e, | |
have h : e.symm (b + c) = e.symm b + e.symm c := (of_equiv_add_group_hom e).add, -- doesn't work | |
simp only [h], -- doesn't work even with sorried `h` | |
sorry}, | |
end |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment