Metamath Proof Explorer


Theorem dfpred4

Description: Alternate definition of the predecessor class when N is a set. (Contributed by Peter Mazsa, 26-Jan-2026)

Ref Expression
Assertion dfpred4 ⊢ N ∈ V → Pred R A N = N R ↾ A -1

Proof

Step Hyp Ref Expression
1 dfpred3g ⊢ N ∈ V → Pred R A N = m ∈ A | m R N
2 ec1cnvres ⊢ N ∈ V → N R ↾ A -1 = m ∈ A | m R N
3 1 2 eqtr4d ⊢ N ∈ V → Pred R A N = N R ↾ A -1