Metamath Proof Explorer


Theorem 1arymaptf1o

Description: The mapping of unary (endo)functions is a one-to-one function onto the set of endofunctions. (Contributed by AV, 19-May-2024)

Ref Expression
Hypothesis 1arymaptfv.h ⊢ H = h ∈ 1 -aryF X ⟼ x ∈ X ⟼ h ⁡ 0 x
Assertion 1arymaptf1o ⊢ X ∈ V → H : 1 -aryF X ⟶ 1-1 onto X X

Proof

Step Hyp Ref Expression
1 1arymaptfv.h ⊢ H = h ∈ 1 -aryF X ⟼ x ∈ X ⟼ h ⁡ 0 x
2 1 1arymaptf1 ⊢ X ∈ V → H : 1 -aryF X ⟶ 1-1 X X
3 1 1arymaptfo ⊢ X ∈ V → H : 1 -aryF X ⟶ onto X X
4 df-f1o ⊢ H : 1 -aryF X ⟶ 1-1 onto X X ↔ H : 1 -aryF X ⟶ 1-1 X X ∧ H : 1 -aryF X ⟶ onto X X
5 2 3 4 sylanbrc ⊢ X ∈ V → H : 1 -aryF X ⟶ 1-1 onto X X