Metamath Proof Explorer


Theorem linethrueu

Description: There is a unique line going through any two distinct points. Theorem 6.19 of Schwabhauser p. 46. (Contributed by Scott Fenton, 29-Oct-2013) (Revised by Mario Carneiro, 19-Apr-2014)

Ref Expression
Assertion linethrueu ⊢ N ∈ ℕ ∧ P ∈ 𝔼 ⁡ N ∧ Q ∈ 𝔼 ⁡ N ∧ P ≠ Q → ∃! x ∈ LinesEE P ∈ x ∧ Q ∈ x

Proof

Step Hyp Ref Expression
1 hilbert1.1 ⊢ N ∈ ℕ ∧ P ∈ 𝔼 ⁡ N ∧ Q ∈ 𝔼 ⁡ N ∧ P ≠ Q → ∃ x ∈ LinesEE P ∈ x ∧ Q ∈ x
2 simpr3 ⊢ N ∈ ℕ ∧ P ∈ 𝔼 ⁡ N ∧ Q ∈ 𝔼 ⁡ N ∧ P ≠ Q → P ≠ Q
3 hilbert1.2 ⊢ P ≠ Q → ∃* x ∈ LinesEE P ∈ x ∧ Q ∈ x
4 2 3 syl ⊢ N ∈ ℕ ∧ P ∈ 𝔼 ⁡ N ∧ Q ∈ 𝔼 ⁡ N ∧ P ≠ Q → ∃* x ∈ LinesEE P ∈ x ∧ Q ∈ x
5 reu5 ⊢ ∃! x ∈ LinesEE P ∈ x ∧ Q ∈ x ↔ ∃ x ∈ LinesEE P ∈ x ∧ Q ∈ x ∧ ∃* x ∈ LinesEE P ∈ x ∧ Q ∈ x
6 1 4 5 sylanbrc ⊢ N ∈ ℕ ∧ P ∈ 𝔼 ⁡ N ∧ Q ∈ 𝔼 ⁡ N ∧ P ≠ Q → ∃! x ∈ LinesEE P ∈ x ∧ Q ∈ x