Metamath Proof Explorer


Definition df-wlim

Description: Define the class of limit points of a well-founded set. (Contributed by Scott Fenton, 15-Jun-2018) (Revised by AV, 10-Oct-2021)

Ref Expression
Assertion df-wlim WLim ( 𝑅 , 𝐴 ) = { 𝑥 ∈ 𝐴 ∣ ( 𝑥 ≠ inf ( 𝐴 , 𝐴 , 𝑅 ) ∧ 𝑥 = sup ( Pred ( 𝑅 , 𝐴 , 𝑥 ) , 𝐴 , 𝑅 ) ) }

Detailed syntax breakdown

Step Hyp Ref Expression
0 cR ⊢ 𝑅
1 cA ⊢ 𝐴
2 1 0 cwlim ⊢ WLim ( 𝑅 , 𝐴 )
3 vx ⊢ 𝑥
4 3 cv ⊢ 𝑥
5 1 1 0 cinf ⊢ inf ( 𝐴 , 𝐴 , 𝑅 )
6 4 5 wne ⊢ 𝑥 ≠ inf ( 𝐴 , 𝐴 , 𝑅 )
7 1 0 4 cpred ⊢ Pred ( 𝑅 , 𝐴 , 𝑥 )
8 7 1 0 csup ⊢ sup ( Pred ( 𝑅 , 𝐴 , 𝑥 ) , 𝐴 , 𝑅 )
9 4 8 wceq ⊢ 𝑥 = sup ( Pred ( 𝑅 , 𝐴 , 𝑥 ) , 𝐴 , 𝑅 )
10 6 9 wa ⊢ ( 𝑥 ≠ inf ( 𝐴 , 𝐴 , 𝑅 ) ∧ 𝑥 = sup ( Pred ( 𝑅 , 𝐴 , 𝑥 ) , 𝐴 , 𝑅 ) )
11 10 3 1 crab ⊢ { 𝑥 ∈ 𝐴 ∣ ( 𝑥 ≠ inf ( 𝐴 , 𝐴 , 𝑅 ) ∧ 𝑥 = sup ( Pred ( 𝑅 , 𝐴 , 𝑥 ) , 𝐴 , 𝑅 ) ) }
12 2 11 wceq ⊢ WLim ( 𝑅 , 𝐴 ) = { 𝑥 ∈ 𝐴 ∣ ( 𝑥 ≠ inf ( 𝐴 , 𝐴 , 𝑅 ) ∧ 𝑥 = sup ( Pred ( 𝑅 , 𝐴 , 𝑥 ) , 𝐴 , 𝑅 ) ) }