Metamath Proof Explorer


Theorem wesn

Description: Well-ordering of a singleton. (Contributed by Mario Carneiro, 28-Dec-2014)

Ref Expression
Assertion wesn ( Rel 𝑅 → ( 𝑅 We { 𝐴 } ↔ ¬ 𝐴 𝑅 𝐴 ) )

Proof

Step Hyp Ref Expression
1 frsn ( Rel 𝑅 → ( 𝑅 Fr { 𝐴 } ↔ ¬ 𝐴 𝑅 𝐴 ) )
2 sosn ( Rel 𝑅 → ( 𝑅 Or { 𝐴 } ↔ ¬ 𝐴 𝑅 𝐴 ) )
3 1 2 anbi12d ( Rel 𝑅 → ( ( 𝑅 Fr { 𝐴 } ∧ 𝑅 Or { 𝐴 } ) ↔ ( ¬ 𝐴 𝑅 𝐴 ∧ ¬ 𝐴 𝑅 𝐴 ) ) )
4 df-we ( 𝑅 We { 𝐴 } ↔ ( 𝑅 Fr { 𝐴 } ∧ 𝑅 Or { 𝐴 } ) )
5 pm4.24 ( ¬ 𝐴 𝑅 𝐴 ↔ ( ¬ 𝐴 𝑅 𝐴 ∧ ¬ 𝐴 𝑅 𝐴 ) )
6 3 4 5 3bitr4g ( Rel 𝑅 → ( 𝑅 We { 𝐴 } ↔ ¬ 𝐴 𝑅 𝐴 ) )