End Circumcenter.
(* TODO investigate bug Hint Resolve/Section *)
Hint Resolve
is_circumcenter_perm_1
is_circumcenter_perm_2
is_circumcenter_perm_3
is_circumcenter_perm_4
is_circumcenter_perm_5 : Circumcenter.
Hint Resolve is_circumcenter_cop : cop.
Section Circumcenter2 .
Context `{TE:Tarski_euclidean}.
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Lemma is_circumcenter_uniqueness :
forall A B C O O',
A<>B -> B<>C -> A<>C ->
is_circumcenter O A B C ->
is_circumcenter O' A B C ->
O = O'.