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Description: Any class B has at most one supremum in A (where R is interpreted as 'less than'). (Contributed by NM, 5-May-1999) (Revised by Mario Carneiro, 24-Dec-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | supmo.1 | ⊢ ( 𝜑 → 𝑅 Or 𝐴 ) | |
| Assertion | supmo | ⊢ ( 𝜑 → ∃* 𝑥 ∈ 𝐴 ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | supmo.1 | ⊢ ( 𝜑 → 𝑅 Or 𝐴 ) | |
| 2 | ancom | ⊢ ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ) ↔ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ) ) | |
| 3 | 2 | anbi2ci | ⊢ ( ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ) ∧ ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) ↔ ( ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ∧ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ) ) ) |
| 4 | an42 | ⊢ ( ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ∧ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) ↔ ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ) ∧ ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) ) | |
| 5 | an42 | ⊢ ( ( ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ) ∧ ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ) ) ↔ ( ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ∧ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ) ) ) | |
| 6 | 3 4 5 | 3bitr4i | ⊢ ( ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ∧ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) ↔ ( ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ) ∧ ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ) ) ) |
| 7 | ralnex | ⊢ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ↔ ¬ ∃ 𝑦 ∈ 𝐵 𝑥 𝑅 𝑦 ) | |
| 8 | breq1 | ⊢ ( 𝑦 = 𝑥 → ( 𝑦 𝑅 𝑤 ↔ 𝑥 𝑅 𝑤 ) ) | |
| 9 | breq1 | ⊢ ( 𝑦 = 𝑥 → ( 𝑦 𝑅 𝑧 ↔ 𝑥 𝑅 𝑧 ) ) | |
| 10 | 9 | rexbidv | ⊢ ( 𝑦 = 𝑥 → ( ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ↔ ∃ 𝑧 ∈ 𝐵 𝑥 𝑅 𝑧 ) ) |
| 11 | 8 10 | imbi12d | ⊢ ( 𝑦 = 𝑥 → ( ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ↔ ( 𝑥 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑥 𝑅 𝑧 ) ) ) |
| 12 | 11 | rspcva | ⊢ ( ( 𝑥 ∈ 𝐴 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) → ( 𝑥 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑥 𝑅 𝑧 ) ) |
| 13 | breq2 | ⊢ ( 𝑦 = 𝑧 → ( 𝑥 𝑅 𝑦 ↔ 𝑥 𝑅 𝑧 ) ) | |
| 14 | 13 | cbvrexvw | ⊢ ( ∃ 𝑦 ∈ 𝐵 𝑥 𝑅 𝑦 ↔ ∃ 𝑧 ∈ 𝐵 𝑥 𝑅 𝑧 ) |
| 15 | 12 14 | imbitrrdi | ⊢ ( ( 𝑥 ∈ 𝐴 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) → ( 𝑥 𝑅 𝑤 → ∃ 𝑦 ∈ 𝐵 𝑥 𝑅 𝑦 ) ) |
| 16 | 15 | con3d | ⊢ ( ( 𝑥 ∈ 𝐴 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) → ( ¬ ∃ 𝑦 ∈ 𝐵 𝑥 𝑅 𝑦 → ¬ 𝑥 𝑅 𝑤 ) ) |
| 17 | 7 16 | biimtrid | ⊢ ( ( 𝑥 ∈ 𝐴 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) → ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 → ¬ 𝑥 𝑅 𝑤 ) ) |
| 18 | 17 | expimpd | ⊢ ( 𝑥 ∈ 𝐴 → ( ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ) → ¬ 𝑥 𝑅 𝑤 ) ) |
| 19 | 18 | ad2antrl | ⊢ ( ( 𝑅 Or 𝐴 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑤 ∈ 𝐴 ) ) → ( ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ) → ¬ 𝑥 𝑅 𝑤 ) ) |
| 20 | ralnex | ⊢ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ↔ ¬ ∃ 𝑦 ∈ 𝐵 𝑤 𝑅 𝑦 ) | |
| 21 | breq1 | ⊢ ( 𝑦 = 𝑤 → ( 𝑦 𝑅 𝑥 ↔ 𝑤 𝑅 𝑥 ) ) | |
| 22 | breq1 | ⊢ ( 𝑦 = 𝑤 → ( 𝑦 𝑅 𝑧 ↔ 𝑤 𝑅 𝑧 ) ) | |
| 23 | 22 | rexbidv | ⊢ ( 𝑦 = 𝑤 → ( ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ↔ ∃ 𝑧 ∈ 𝐵 𝑤 𝑅 𝑧 ) ) |
| 24 | 21 23 | imbi12d | ⊢ ( 𝑦 = 𝑤 → ( ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ↔ ( 𝑤 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑤 𝑅 𝑧 ) ) ) |
| 25 | 24 | rspcva | ⊢ ( ( 𝑤 ∈ 𝐴 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) → ( 𝑤 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑤 𝑅 𝑧 ) ) |
| 26 | breq2 | ⊢ ( 𝑦 = 𝑧 → ( 𝑤 𝑅 𝑦 ↔ 𝑤 𝑅 𝑧 ) ) | |
| 27 | 26 | cbvrexvw | ⊢ ( ∃ 𝑦 ∈ 𝐵 𝑤 𝑅 𝑦 ↔ ∃ 𝑧 ∈ 𝐵 𝑤 𝑅 𝑧 ) |
| 28 | 25 27 | imbitrrdi | ⊢ ( ( 𝑤 ∈ 𝐴 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) → ( 𝑤 𝑅 𝑥 → ∃ 𝑦 ∈ 𝐵 𝑤 𝑅 𝑦 ) ) |
| 29 | 28 | con3d | ⊢ ( ( 𝑤 ∈ 𝐴 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) → ( ¬ ∃ 𝑦 ∈ 𝐵 𝑤 𝑅 𝑦 → ¬ 𝑤 𝑅 𝑥 ) ) |
| 30 | 20 29 | biimtrid | ⊢ ( ( 𝑤 ∈ 𝐴 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) → ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 → ¬ 𝑤 𝑅 𝑥 ) ) |
| 31 | 30 | expimpd | ⊢ ( 𝑤 ∈ 𝐴 → ( ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ) → ¬ 𝑤 𝑅 𝑥 ) ) |
| 32 | 31 | ad2antll | ⊢ ( ( 𝑅 Or 𝐴 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑤 ∈ 𝐴 ) ) → ( ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ) → ¬ 𝑤 𝑅 𝑥 ) ) |
| 33 | 19 32 | anim12d | ⊢ ( ( 𝑅 Or 𝐴 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑤 ∈ 𝐴 ) ) → ( ( ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ) ∧ ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ∧ ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ) ) → ( ¬ 𝑥 𝑅 𝑤 ∧ ¬ 𝑤 𝑅 𝑥 ) ) ) |
| 34 | 6 33 | biimtrid | ⊢ ( ( 𝑅 Or 𝐴 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑤 ∈ 𝐴 ) ) → ( ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ∧ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) → ( ¬ 𝑥 𝑅 𝑤 ∧ ¬ 𝑤 𝑅 𝑥 ) ) ) |
| 35 | sotrieq2 | ⊢ ( ( 𝑅 Or 𝐴 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑤 ∈ 𝐴 ) ) → ( 𝑥 = 𝑤 ↔ ( ¬ 𝑥 𝑅 𝑤 ∧ ¬ 𝑤 𝑅 𝑥 ) ) ) | |
| 36 | 34 35 | sylibrd | ⊢ ( ( 𝑅 Or 𝐴 ∧ ( 𝑥 ∈ 𝐴 ∧ 𝑤 ∈ 𝐴 ) ) → ( ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ∧ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) → 𝑥 = 𝑤 ) ) |
| 37 | 36 | ralrimivva | ⊢ ( 𝑅 Or 𝐴 → ∀ 𝑥 ∈ 𝐴 ∀ 𝑤 ∈ 𝐴 ( ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ∧ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) → 𝑥 = 𝑤 ) ) |
| 38 | 1 37 | syl | ⊢ ( 𝜑 → ∀ 𝑥 ∈ 𝐴 ∀ 𝑤 ∈ 𝐴 ( ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ∧ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) → 𝑥 = 𝑤 ) ) |
| 39 | breq1 | ⊢ ( 𝑥 = 𝑤 → ( 𝑥 𝑅 𝑦 ↔ 𝑤 𝑅 𝑦 ) ) | |
| 40 | 39 | notbid | ⊢ ( 𝑥 = 𝑤 → ( ¬ 𝑥 𝑅 𝑦 ↔ ¬ 𝑤 𝑅 𝑦 ) ) |
| 41 | 40 | ralbidv | ⊢ ( 𝑥 = 𝑤 → ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ↔ ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ) ) |
| 42 | breq2 | ⊢ ( 𝑥 = 𝑤 → ( 𝑦 𝑅 𝑥 ↔ 𝑦 𝑅 𝑤 ) ) | |
| 43 | 42 | imbi1d | ⊢ ( 𝑥 = 𝑤 → ( ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ↔ ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) |
| 44 | 43 | ralbidv | ⊢ ( 𝑥 = 𝑤 → ( ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ↔ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) |
| 45 | 41 44 | anbi12d | ⊢ ( 𝑥 = 𝑤 → ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ↔ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) ) |
| 46 | 45 | rmo4 | ⊢ ( ∃* 𝑥 ∈ 𝐴 ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ↔ ∀ 𝑥 ∈ 𝐴 ∀ 𝑤 ∈ 𝐴 ( ( ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ∧ ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑤 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑤 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) → 𝑥 = 𝑤 ) ) |
| 47 | 38 46 | sylibr | ⊢ ( 𝜑 → ∃* 𝑥 ∈ 𝐴 ( ∀ 𝑦 ∈ 𝐵 ¬ 𝑥 𝑅 𝑦 ∧ ∀ 𝑦 ∈ 𝐴 ( 𝑦 𝑅 𝑥 → ∃ 𝑧 ∈ 𝐵 𝑦 𝑅 𝑧 ) ) ) |