Description: The successor-predecessor exists. (Contributed by Peter Mazsa, 12-Jan-2026)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | preex | ⊢ pre 𝑁 ∈ V |
| 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 |