Description: A binary (endo)function on a set X . (Contributed by AV, 20-May-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 2aryfvalel | ⊢ ( 𝑋 ∈ 𝑉 → ( 𝐹 ∈ ( 2 -aryF 𝑋 ) ↔ 𝐹 : ( 𝑋 ↑m { 0 , 1 } ) ⟶ 𝑋 ) ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 2nn0 | ⊢ 2 ∈ ℕ0 | |
| 2 | fzo0to2pr | ⊢ ( 0 ..^ 2 ) = { 0 , 1 } | |
| 3 | 2 | eqcomi | ⊢ { 0 , 1 } = ( 0 ..^ 2 ) | 
| 4 | 3 | naryfvalel | ⊢ ( ( 2 ∈ ℕ0 ∧ 𝑋 ∈ 𝑉 ) → ( 𝐹 ∈ ( 2 -aryF 𝑋 ) ↔ 𝐹 : ( 𝑋 ↑m { 0 , 1 } ) ⟶ 𝑋 ) ) | 
| 5 | 1 4 | mpan | ⊢ ( 𝑋 ∈ 𝑉 → ( 𝐹 ∈ ( 2 -aryF 𝑋 ) ↔ 𝐹 : ( 𝑋 ↑m { 0 , 1 } ) ⟶ 𝑋 ) ) |