Metamath Proof Explorer


Theorem broutsideof

Description: Binary relation form of OutsideOf . Theorem 6.4 of Schwabhauser p. 43. (Contributed by Scott Fenton, 17-Oct-2013) (Revised by Mario Carneiro, 19-Apr-2014)

Ref Expression
Assertion broutsideof ( 𝑃 OutsideOf ⟨ 𝐴 , 𝐵 ⟩ ↔ ( 𝑃 Colinear ⟨ 𝐴 , 𝐵 ⟩ ∧ ¬ 𝑃 Btwn ⟨ 𝐴 , 𝐵 ⟩ ) )

Proof

Step Hyp Ref Expression
1 df-outsideof OutsideOf = ( Colinear ∖ Btwn )
2 1 breqi ( 𝑃 OutsideOf ⟨ 𝐴 , 𝐵 ⟩ ↔ 𝑃 ( Colinear ∖ Btwn ) ⟨ 𝐴 , 𝐵 ⟩ )
3 brdif ( 𝑃 ( Colinear ∖ Btwn ) ⟨ 𝐴 , 𝐵 ⟩ ↔ ( 𝑃 Colinear ⟨ 𝐴 , 𝐵 ⟩ ∧ ¬ 𝑃 Btwn ⟨ 𝐴 , 𝐵 ⟩ ) )
4 2 3 bitri ( 𝑃 OutsideOf ⟨ 𝐴 , 𝐵 ⟩ ↔ ( 𝑃 Colinear ⟨ 𝐴 , 𝐵 ⟩ ∧ ¬ 𝑃 Btwn ⟨ 𝐴 , 𝐵 ⟩ ) )