Theorem: EuclideanGeometry.OrthocentricSystem.exists_circumradius_eq
File: Mathlib/Geometry/Euclidean/MongePoint.lean

Proof steps:
state_before: V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
ho : OrthocentricSystem s
⊢ ∃ r, ∀ (t : Triangle ℝ P), Set.range t.points ⊆ s → Simplex.circumradius t = r
state_after: case intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
⊢ ∃ r, ∀ (t : Triangle ℝ P), Set.range t.points ⊆ s → Simplex.circumradius t = r
tactic: rcases ho with ⟨t, hto, hts⟩
state_before: case intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
⊢ ∃ r, ∀ (t : Triangle ℝ P), Set.range t.points ⊆ s → Simplex.circumradius t = r
state_after: case h
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
⊢ ∀ (t_1 : Triangle ℝ P), Set.range t_1.points ⊆ s → Simplex.circumradius t_1 = Simplex.circumradius t
tactic: use t.circumradius
state_before: case h
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
⊢ ∀ (t_1 : Triangle ℝ P), Set.range t_1.points ⊆ s → Simplex.circumradius t_1 = Simplex.circumradius t
state_after: case h
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
tactic: intro t₂ ht₂
state_before: case h
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
state_after: case h
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ ht₂s : Set.range t₂.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
tactic: have ht₂s := ht₂
state_before: case h
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ ht₂s : Set.range t₂.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
state_after: case h
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
tactic: rw [hts] at ht₂
state_before: case h
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
state_after: case h.intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
c : P
hc : c ∈ affineSpan ℝ (Set.range t.points)
h : ∀ p₁ ∈ Set.range t₂.points, dist p₁ c = Simplex.circumradius t
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
tactic: rcases exists_dist_eq_circumradius_of_subset_insert_orthocenter hto ht₂
      t₂.independent.injective with
    ⟨c, hc, h⟩
state_before: case h.intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
c : P
hc : c ∈ affineSpan ℝ (Set.range t.points)
h : ∀ p₁ ∈ Set.range t₂.points, dist p₁ c = Simplex.circumradius t
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
state_after: case h.intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
c : P
hc : c ∈ affineSpan ℝ (Set.range t.points)
h : ∀ (i : Fin 3), dist (t₂.points i) c = Simplex.circumradius t
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
tactic: rw [Set.forall_mem_range] at h
state_before: case h.intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
c : P
hc : c ∈ affineSpan ℝ (Set.range t.points)
h : ∀ (i : Fin 3), dist (t₂.points i) c = Simplex.circumradius t
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
state_after: case h.intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
c : P
hc : c ∈ affineSpan ℝ (Set.range t.points)
h : ∀ (i : Fin 3), dist (t₂.points i) c = Simplex.circumradius t
hs : Set.range t.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
tactic: have hs : Set.range t.points ⊆ s := by
    rw [hts]
    exact Set.subset_insert _ _
state_before: case h.intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
c : P
hc : c ∈ affineSpan ℝ (Set.range t.points)
h : ∀ (i : Fin 3), dist (t₂.points i) c = Simplex.circumradius t
hs : Set.range t.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
state_after: case h.intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
c : P
hc : c ∈ affineSpan ℝ (Set.range t₂.points)
h : ∀ (i : Fin 3), dist (t₂.points i) c = Simplex.circumradius t
hs : Set.range t.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
tactic: rw [affineSpan_of_orthocentricSystem ⟨t, hto, hts⟩ hs t.independent.injective,
    ← affineSpan_of_orthocentricSystem ⟨t, hto, hts⟩ ht₂s t₂.independent.injective] at hc
state_before: case h.intro.intro
V : Type u_1
P : Type u_2
inst✝³ : NormedAddCommGroup V
inst✝² : InnerProductSpace ℝ V
inst✝¹ : MetricSpace P
inst✝ : NormedAddTorsor V P
s : Set P
t : Triangle ℝ P
hto : t.orthocenter ∉ Set.range t.points
hts : s = insert t.orthocenter (Set.range t.points)
t₂ : Triangle ℝ P
ht₂ : Set.range t₂.points ⊆ insert t.orthocenter (Set.range t.points)
ht₂s : Set.range t₂.points ⊆ s
c : P
hc : c ∈ affineSpan ℝ (Set.range t₂.points)
h : ∀ (i : Fin 3), dist (t₂.points i) c = Simplex.circumradius t
hs : Set.range t.points ⊆ s
⊢ Simplex.circumradius t₂ = Simplex.circumradius t
state_after: no goals
tactic: exact (t₂.eq_circumradius_of_dist_eq hc h).symm