Description: Reverse closure for the class of universal property in opposite categories. (Contributed by Zhi Wang, 4-Nov-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | oppcuprcl2.x | ⊢ ( 𝜑 → 𝑋 ( 〈 𝐹 , 𝐺 〉 ( 𝑂 UP 𝑃 ) 𝑊 ) 𝑀 ) | |
| oppcuprcl4.o | ⊢ 𝑂 = ( oppCat ‘ 𝐷 ) | ||
| oppcuprcl4.b | ⊢ 𝐵 = ( Base ‘ 𝐷 ) | ||
| Assertion | oppcuprcl4 | ⊢ ( 𝜑 → 𝑋 ∈ 𝐵 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | oppcuprcl2.x | ⊢ ( 𝜑 → 𝑋 ( 〈 𝐹 , 𝐺 〉 ( 𝑂 UP 𝑃 ) 𝑊 ) 𝑀 ) | |
| 2 | oppcuprcl4.o | ⊢ 𝑂 = ( oppCat ‘ 𝐷 ) | |
| 3 | oppcuprcl4.b | ⊢ 𝐵 = ( Base ‘ 𝐷 ) | |
| 4 | 2 3 | oppcbas | ⊢ 𝐵 = ( Base ‘ 𝑂 ) |
| 5 | 1 4 | uprcl4 | ⊢ ( 𝜑 → 𝑋 ∈ 𝐵 ) |