Metamath Proof Explorer


Theorem fun11uni

Description: The union of a chain (with respect to inclusion) of one-to-one functions is a one-to-one function. (Contributed by NM, 11-Aug-2004)

Ref Expression
Assertion fun11uni ⊢ ∀ f ∈ A Fun ⁡ f ∧ Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → Fun ⁡ ⋃ A ∧ Fun ⁡ ⋃ A -1

Proof

Step Hyp Ref Expression
1 simpl ⊢ Fun ⁡ f ∧ Fun ⁡ f -1 → Fun ⁡ f
2 1 anim1i ⊢ Fun ⁡ f ∧ Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → Fun ⁡ f ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f
3 2 ralimi ⊢ ∀ f ∈ A Fun ⁡ f ∧ Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → ∀ f ∈ A Fun ⁡ f ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f
4 fununi ⊢ ∀ f ∈ A Fun ⁡ f ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → Fun ⁡ ⋃ A
5 3 4 syl ⊢ ∀ f ∈ A Fun ⁡ f ∧ Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → Fun ⁡ ⋃ A
6 simpr ⊢ Fun ⁡ f ∧ Fun ⁡ f -1 → Fun ⁡ f -1
7 6 anim1i ⊢ Fun ⁡ f ∧ Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f
8 7 ralimi ⊢ ∀ f ∈ A Fun ⁡ f ∧ Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → ∀ f ∈ A Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f
9 funcnvuni ⊢ ∀ f ∈ A Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → Fun ⁡ ⋃ A -1
10 8 9 syl ⊢ ∀ f ∈ A Fun ⁡ f ∧ Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → Fun ⁡ ⋃ A -1
11 5 10 jca ⊢ ∀ f ∈ A Fun ⁡ f ∧ Fun ⁡ f -1 ∧ ∀ g ∈ A f ⊆ g ∨ g ⊆ f → Fun ⁡ ⋃ A ∧ Fun ⁡ ⋃ A -1