Metamath Proof Explorer


Theorem preex

Description: The successor-predecessor exists. (Contributed by Peter Mazsa, 12-Jan-2026)

Ref Expression
Assertion preex pre 𝑁 ∈ V

Proof

Step Hyp Ref Expression
1 df-pre pre 𝑁 = ( ℩ 𝑚 𝑚 ∈ Pred ( SucMap , dom SucMap , 𝑁 ) )
2 iotaex ( ℩ 𝑚 𝑚 ∈ Pred ( SucMap , dom SucMap , 𝑁 ) ) ∈ V
3 1 2 eqeltri pre 𝑁 ∈ V