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Description: Restricted uniqueness implies restricted "at most one" through implication, analogous to euimmo . (Contributed by Alexander van der Vekens, 25-Jun-2017)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | reuimrmo | ⊢ ( ∀ 𝑥 ∈ 𝐴 ( 𝜑 → 𝜓 ) → ( ∃! 𝑥 ∈ 𝐴 𝜓 → ∃* 𝑥 ∈ 𝐴 𝜑 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | reurmo | ⊢ ( ∃! 𝑥 ∈ 𝐴 𝜓 → ∃* 𝑥 ∈ 𝐴 𝜓 ) | |
| 2 | rmoim | ⊢ ( ∀ 𝑥 ∈ 𝐴 ( 𝜑 → 𝜓 ) → ( ∃* 𝑥 ∈ 𝐴 𝜓 → ∃* 𝑥 ∈ 𝐴 𝜑 ) ) | |
| 3 | 1 2 | syl5 | ⊢ ( ∀ 𝑥 ∈ 𝐴 ( 𝜑 → 𝜓 ) → ( ∃! 𝑥 ∈ 𝐴 𝜓 → ∃* 𝑥 ∈ 𝐴 𝜑 ) ) |