Metamath Proof Explorer
		
		
		
		Description:  The span of a singleton in Hilbert space is a closed subspace.
       (Contributed by NM, 3-Jun-2004)  (New usage is discouraged.)
		
			
				
					 | 
					 | 
					Ref | 
					Expression | 
				
					
						 | 
						Hypothesis | 
						spansnch.1 | 
						⊢ 𝐴  ∈   ℋ  | 
					
				
					 | 
					Assertion | 
					spansnchi | 
					⊢  ( span ‘ { 𝐴 } )  ∈   Cℋ   | 
				
			
		
		
			
				Proof
				
					
						| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							spansnch.1 | 
							⊢ 𝐴  ∈   ℋ  | 
						
						
							| 2 | 
							
								
							 | 
							spansnch | 
							⊢ ( 𝐴  ∈   ℋ  →  ( span ‘ { 𝐴 } )  ∈   Cℋ  )  | 
						
						
							| 3 | 
							
								1 2
							 | 
							ax-mp | 
							⊢ ( span ‘ { 𝐴 } )  ∈   Cℋ   |