Description: Define the partition predicate. (Contributed by Rodolfo Medina, 13-Oct-2010)
Ref | Expression | ||
---|---|---|---|
Assertion | df-prt | ⊢ ( Prt 𝐴 ↔ ∀ 𝑥 ∈ 𝐴 ∀ 𝑦 ∈ 𝐴 ( 𝑥 = 𝑦 ∨ ( 𝑥 ∩ 𝑦 ) = ∅ ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cA | ⊢ 𝐴 | |
1 | 0 | wprt | ⊢ Prt 𝐴 |
2 | vx | ⊢ 𝑥 | |
3 | vy | ⊢ 𝑦 | |
4 | 2 | cv | ⊢ 𝑥 |
5 | 3 | cv | ⊢ 𝑦 |
6 | 4 5 | wceq | ⊢ 𝑥 = 𝑦 |
7 | 4 5 | cin | ⊢ ( 𝑥 ∩ 𝑦 ) |
8 | c0 | ⊢ ∅ | |
9 | 7 8 | wceq | ⊢ ( 𝑥 ∩ 𝑦 ) = ∅ |
10 | 6 9 | wo | ⊢ ( 𝑥 = 𝑦 ∨ ( 𝑥 ∩ 𝑦 ) = ∅ ) |
11 | 10 3 0 | wral | ⊢ ∀ 𝑦 ∈ 𝐴 ( 𝑥 = 𝑦 ∨ ( 𝑥 ∩ 𝑦 ) = ∅ ) |
12 | 11 2 0 | wral | ⊢ ∀ 𝑥 ∈ 𝐴 ∀ 𝑦 ∈ 𝐴 ( 𝑥 = 𝑦 ∨ ( 𝑥 ∩ 𝑦 ) = ∅ ) |
13 | 1 12 | wb | ⊢ ( Prt 𝐴 ↔ ∀ 𝑥 ∈ 𝐴 ∀ 𝑦 ∈ 𝐴 ( 𝑥 = 𝑦 ∨ ( 𝑥 ∩ 𝑦 ) = ∅ ) ) |