Metamath Proof Explorer


Theorem zeroofn

Description: ZeroO is a function on Cat . (Contributed by Zhi Wang, 29-Aug-2024)

Ref Expression
Assertion zeroofn ZeroO Fn Cat

Proof

Step Hyp Ref Expression
1 fvex ( InitO ‘ 𝑐 ) ∈ V
2 1 inex1 ( ( InitO ‘ 𝑐 ) ∩ ( TermO ‘ 𝑐 ) ) ∈ V
3 df-zeroo ZeroO = ( 𝑐 ∈ Cat ↦ ( ( InitO ‘ 𝑐 ) ∩ ( TermO ‘ 𝑐 ) ) )
4 2 3 fnmpti ZeroO Fn Cat