Metamath Proof Explorer
		
		
		
		Description:  A weak universe is closed under the converse operator.  (Contributed by Mario Carneiro, 2-Jan-2017)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypotheses | wun0.1 | ⊢ ( 𝜑  →  𝑈  ∈  WUni ) | 
					
						|  |  | wunop.2 | ⊢ ( 𝜑  →  𝐴  ∈  𝑈 ) | 
				
					|  | Assertion | wuncnv | ⊢  ( 𝜑  →  ◡ 𝐴  ∈  𝑈 ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | wun0.1 | ⊢ ( 𝜑  →  𝑈  ∈  WUni ) | 
						
							| 2 |  | wunop.2 | ⊢ ( 𝜑  →  𝐴  ∈  𝑈 ) | 
						
							| 3 | 1 2 | wunrn | ⊢ ( 𝜑  →  ran  𝐴  ∈  𝑈 ) | 
						
							| 4 | 1 2 | wundm | ⊢ ( 𝜑  →  dom  𝐴  ∈  𝑈 ) | 
						
							| 5 | 1 3 4 | wunxp | ⊢ ( 𝜑  →  ( ran  𝐴  ×  dom  𝐴 )  ∈  𝑈 ) | 
						
							| 6 |  | cnvssrndm | ⊢ ◡ 𝐴  ⊆  ( ran  𝐴  ×  dom  𝐴 ) | 
						
							| 7 | 6 | a1i | ⊢ ( 𝜑  →  ◡ 𝐴  ⊆  ( ran  𝐴  ×  dom  𝐴 ) ) | 
						
							| 8 | 1 5 7 | wunss | ⊢ ( 𝜑  →  ◡ 𝐴  ∈  𝑈 ) |