Metamath Proof Explorer


Theorem 1aryfvalel

Description: A unary (endo)function on a set X . (Contributed by AV, 15-May-2024)

Ref Expression
Assertion 1aryfvalel ( 𝑋 ∈ 𝑉 → ( 𝐹 ∈ ( 1 -aryF 𝑋 ) ↔ 𝐹 : ( 𝑋 ↑m { 0 } ) ⟶ 𝑋 ) )

Proof

Step Hyp Ref Expression
1 1nn0 ⊢ 1 ∈ ℕ0
2 fzo01 ⊢ ( 0 ..^ 1 ) = { 0 }
3 2 eqcomi ⊢ { 0 } = ( 0 ..^ 1 )
4 3 naryfvalel ⊢ ( ( 1 ∈ ℕ0 ∧ 𝑋 ∈ 𝑉 ) → ( 𝐹 ∈ ( 1 -aryF 𝑋 ) ↔ 𝐹 : ( 𝑋 ↑m { 0 } ) ⟶ 𝑋 ) )
5 1 4 mpan ⊢ ( 𝑋 ∈ 𝑉 → ( 𝐹 ∈ ( 1 -aryF 𝑋 ) ↔ 𝐹 : ( 𝑋 ↑m { 0 } ) ⟶ 𝑋 ) )