Metamath Proof Explorer


Theorem reldmprcof

Description: The domain of -o.F is a relation. (Contributed by Zhi Wang, 2-Nov-2025)

Ref Expression
Assertion reldmprcof Rel dom −∘F

Proof

Step Hyp Ref Expression
1 df-prcof −∘F = ( 𝑝 ∈ V , 𝑓 ∈ V ↦ ( 1st𝑝 ) / 𝑑 ( 2nd𝑝 ) / 𝑒 ( 𝑑 Func 𝑒 ) / 𝑏 ⟨ ( 𝑘𝑏 ↦ ( 𝑘func 𝑓 ) ) , ( 𝑘𝑏 , 𝑙𝑏 ↦ ( 𝑎 ∈ ( 𝑘 ( 𝑑 Nat 𝑒 ) 𝑙 ) ↦ ( 𝑎 ∘ ( 1st𝑓 ) ) ) ) ⟩ )
2 1 reldmmpo Rel dom −∘F