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Description: Reverse closure for universal object. (Contributed by Zhi Wang, 17-Nov-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | uobrcl | ⊢ ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) → ( 𝐷 ∈ Cat ∧ 𝐸 ∈ Cat ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eldmg | ⊢ ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) → ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) ↔ ∃ 𝑚 𝑋 ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) 𝑚 ) ) | |
| 2 | 1 | ibi | ⊢ ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) → ∃ 𝑚 𝑋 ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) 𝑚 ) |
| 3 | simpr | ⊢ ( ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) ∧ 𝑋 ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) 𝑚 ) → 𝑋 ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) 𝑚 ) | |
| 4 | 3 | up1st2nd | ⊢ ( ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) ∧ 𝑋 ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) 𝑚 ) → 𝑋 ( 〈 ( 1st ‘ 𝐹 ) , ( 2nd ‘ 𝐹 ) 〉 ( 𝐷 UP 𝐸 ) 𝑊 ) 𝑚 ) |
| 5 | 4 | uprcl2 | ⊢ ( ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) ∧ 𝑋 ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) 𝑚 ) → ( 1st ‘ 𝐹 ) ( 𝐷 Func 𝐸 ) ( 2nd ‘ 𝐹 ) ) |
| 6 | 2 5 | exlimddv | ⊢ ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) → ( 1st ‘ 𝐹 ) ( 𝐷 Func 𝐸 ) ( 2nd ‘ 𝐹 ) ) |
| 7 | 6 | funcrcl2 | ⊢ ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) → 𝐷 ∈ Cat ) |
| 8 | 6 | funcrcl3 | ⊢ ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) → 𝐸 ∈ Cat ) |
| 9 | 7 8 | jca | ⊢ ( 𝑋 ∈ dom ( 𝐹 ( 𝐷 UP 𝐸 ) 𝑊 ) → ( 𝐷 ∈ Cat ∧ 𝐸 ∈ Cat ) ) |