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Description: Lemma for axpr . Eliminate the antecedent of the relevant replacement instance. (Contributed by Rohan Ridenour, 10-Aug-2023) (Proof shortened by Matthew House, 18-Sep-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | axprlem3 | ⊢ ∃ 𝑧 ∀ 𝑤 ( 𝑤 ∈ 𝑧 ↔ ∃ 𝑠 ( 𝑠 ∈ 𝑝 ∧ if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | axrep4v | ⊢ ( ∀ 𝑠 ∃ 𝑧 ∀ 𝑤 ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑧 ) → ∃ 𝑧 ∀ 𝑤 ( 𝑤 ∈ 𝑧 ↔ ∃ 𝑠 ( 𝑠 ∈ 𝑝 ∧ if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) ) ) ) | |
| 2 | ifptru | ⊢ ( ∃ 𝑛 𝑛 ∈ 𝑠 → ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) ↔ 𝑤 = 𝑥 ) ) | |
| 3 | 2 | biimpd | ⊢ ( ∃ 𝑛 𝑛 ∈ 𝑠 → ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑥 ) ) |
| 4 | equeuclr | ⊢ ( 𝑧 = 𝑥 → ( 𝑤 = 𝑥 → 𝑤 = 𝑧 ) ) | |
| 5 | 3 4 | syl9r | ⊢ ( 𝑧 = 𝑥 → ( ∃ 𝑛 𝑛 ∈ 𝑠 → ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑧 ) ) ) |
| 6 | 5 | alrimdv | ⊢ ( 𝑧 = 𝑥 → ( ∃ 𝑛 𝑛 ∈ 𝑠 → ∀ 𝑤 ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑧 ) ) ) |
| 7 | 6 | spimevw | ⊢ ( ∃ 𝑛 𝑛 ∈ 𝑠 → ∃ 𝑧 ∀ 𝑤 ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑧 ) ) |
| 8 | ifpfal | ⊢ ( ¬ ∃ 𝑛 𝑛 ∈ 𝑠 → ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) ↔ 𝑤 = 𝑦 ) ) | |
| 9 | 8 | biimpd | ⊢ ( ¬ ∃ 𝑛 𝑛 ∈ 𝑠 → ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑦 ) ) |
| 10 | equeuclr | ⊢ ( 𝑧 = 𝑦 → ( 𝑤 = 𝑦 → 𝑤 = 𝑧 ) ) | |
| 11 | 9 10 | syl9r | ⊢ ( 𝑧 = 𝑦 → ( ¬ ∃ 𝑛 𝑛 ∈ 𝑠 → ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑧 ) ) ) |
| 12 | 11 | alrimdv | ⊢ ( 𝑧 = 𝑦 → ( ¬ ∃ 𝑛 𝑛 ∈ 𝑠 → ∀ 𝑤 ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑧 ) ) ) |
| 13 | 12 | spimevw | ⊢ ( ¬ ∃ 𝑛 𝑛 ∈ 𝑠 → ∃ 𝑧 ∀ 𝑤 ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑧 ) ) |
| 14 | 7 13 | pm2.61i | ⊢ ∃ 𝑧 ∀ 𝑤 ( if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) → 𝑤 = 𝑧 ) |
| 15 | 1 14 | mpg | ⊢ ∃ 𝑧 ∀ 𝑤 ( 𝑤 ∈ 𝑧 ↔ ∃ 𝑠 ( 𝑠 ∈ 𝑝 ∧ if- ( ∃ 𝑛 𝑛 ∈ 𝑠 , 𝑤 = 𝑥 , 𝑤 = 𝑦 ) ) ) |