Description: A set belongs to its successor. (Contributed by NM, 22-Jun-1994) (Proof shortened by Alan Sare, 18-Feb-2012) (Proof shortened by Scott Fenton, 20-Feb-2012)
Ref | Expression | ||
---|---|---|---|
Hypothesis | sucid.1 | ⊢ 𝐴 ∈ V | |
Assertion | sucid | ⊢ 𝐴 ∈ suc 𝐴 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sucid.1 | ⊢ 𝐴 ∈ V | |
2 | sucidg | ⊢ ( 𝐴 ∈ V → 𝐴 ∈ suc 𝐴 ) | |
3 | 1 2 | ax-mp | ⊢ 𝐴 ∈ suc 𝐴 |