Metamath Proof Explorer


Theorem suceqsneq

Description: One-to-one relationship between the successor operation and the singleton. (Contributed by Peter Mazsa, 31-Dec-2024)

Ref Expression
Assertion suceqsneq ( 𝐴 ∈ 𝑉 → ( suc 𝐴 = suc 𝐵 ↔ { 𝐴 } = { 𝐵 } ) )

Proof

Step Hyp Ref Expression
1 suc11reg ⊢ ( suc 𝐴 = suc 𝐵 ↔ 𝐴 = 𝐵 )
2 sneqbg ⊢ ( 𝐴 ∈ 𝑉 → ( { 𝐴 } = { 𝐵 } ↔ 𝐴 = 𝐵 ) )
3 1 2 bitr4id ⊢ ( 𝐴 ∈ 𝑉 → ( suc 𝐴 = suc 𝐵 ↔ { 𝐴 } = { 𝐵 } ) )