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