Description: If there is a walk W there is a pair of functions representing this walk. (Contributed by Alexander van der Vekens, 22-Jul-2018)
Ref | Expression | ||
---|---|---|---|
Assertion | wlk2f | ⊢ ( 𝑊 ∈ ( Walks ‘ 𝐺 ) → ∃ 𝑓 ∃ 𝑝 𝑓 ( Walks ‘ 𝐺 ) 𝑝 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | wlkcpr | ⊢ ( 𝑊 ∈ ( Walks ‘ 𝐺 ) ↔ ( 1st ‘ 𝑊 ) ( Walks ‘ 𝐺 ) ( 2nd ‘ 𝑊 ) ) | |
2 | fvex | ⊢ ( 1st ‘ 𝑊 ) ∈ V | |
3 | fvex | ⊢ ( 2nd ‘ 𝑊 ) ∈ V | |
4 | breq12 | ⊢ ( ( 𝑓 = ( 1st ‘ 𝑊 ) ∧ 𝑝 = ( 2nd ‘ 𝑊 ) ) → ( 𝑓 ( Walks ‘ 𝐺 ) 𝑝 ↔ ( 1st ‘ 𝑊 ) ( Walks ‘ 𝐺 ) ( 2nd ‘ 𝑊 ) ) ) | |
5 | 2 3 4 | spc2ev | ⊢ ( ( 1st ‘ 𝑊 ) ( Walks ‘ 𝐺 ) ( 2nd ‘ 𝑊 ) → ∃ 𝑓 ∃ 𝑝 𝑓 ( Walks ‘ 𝐺 ) 𝑝 ) |
6 | 1 5 | sylbi | ⊢ ( 𝑊 ∈ ( Walks ‘ 𝐺 ) → ∃ 𝑓 ∃ 𝑝 𝑓 ( Walks ‘ 𝐺 ) 𝑝 ) |