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Description: Lemma for prter2 and also a property of partitions . (Contributed by Rodolfo Medina, 15-Oct-2010) (Revised by Mario Carneiro, 12-Aug-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | prtlem13.1 | ⊢ ∼ = { 〈 𝑥 , 𝑦 〉 ∣ ∃ 𝑢 ∈ 𝐴 ( 𝑥 ∈ 𝑢 ∧ 𝑦 ∈ 𝑢 ) } | |
| Assertion | prtlem400 | ⊢ ¬ ∅ ∈ ( ∪ 𝐴 / ∼ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | prtlem13.1 | ⊢ ∼ = { 〈 𝑥 , 𝑦 〉 ∣ ∃ 𝑢 ∈ 𝐴 ( 𝑥 ∈ 𝑢 ∧ 𝑦 ∈ 𝑢 ) } | |
| 2 | neirr | ⊢ ¬ ∅ ≠ ∅ | |
| 3 | 1 | prtlem16 | ⊢ dom ∼ = ∪ 𝐴 |
| 4 | elqsn0 | ⊢ ( ( dom ∼ = ∪ 𝐴 ∧ ∅ ∈ ( ∪ 𝐴 / ∼ ) ) → ∅ ≠ ∅ ) | |
| 5 | 3 4 | mpan | ⊢ ( ∅ ∈ ( ∪ 𝐴 / ∼ ) → ∅ ≠ ∅ ) |
| 6 | 2 5 | mto | ⊢ ¬ ∅ ∈ ( ∪ 𝐴 / ∼ ) |