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 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | dfpred3g | ⊢ ( 𝑁 ∈ 𝑉 → Pred ( 𝑅 , 𝐴 , 𝑁 ) = { 𝑚 ∈ 𝐴 ∣ 𝑚 𝑅 𝑁 } ) | |
| 2 | ec1cnvres | ⊢ ( 𝑁 ∈ 𝑉 → [ 𝑁 ] ◡ ( 𝑅 ↾ 𝐴 ) = { 𝑚 ∈ 𝐴 ∣ 𝑚 𝑅 𝑁 } ) | |
| 3 | 1 2 | eqtr4d | ⊢ ( 𝑁 ∈ 𝑉 → Pred ( 𝑅 , 𝐴 , 𝑁 ) = [ 𝑁 ] ◡ ( 𝑅 ↾ 𝐴 ) ) |