Metamath Proof Explorer
		
		
		
		Description:  An infinite Cartesian product is a subset of set exponentiation.  Remark
       in Enderton p. 54.  (Contributed by NM, 28-Sep-2006)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypothesis | ixpssmap.2 | ⊢ 𝐵  ∈  V | 
				
					|  | Assertion | ixpssmap | ⊢  X 𝑥  ∈  𝐴 𝐵  ⊆  ( ∪  𝑥  ∈  𝐴 𝐵  ↑m  𝐴 ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ixpssmap.2 | ⊢ 𝐵  ∈  V | 
						
							| 2 | 1 | rgenw | ⊢ ∀ 𝑥  ∈  𝐴 𝐵  ∈  V | 
						
							| 3 |  | ixpssmapg | ⊢ ( ∀ 𝑥  ∈  𝐴 𝐵  ∈  V  →  X 𝑥  ∈  𝐴 𝐵  ⊆  ( ∪  𝑥  ∈  𝐴 𝐵  ↑m  𝐴 ) ) | 
						
							| 4 | 2 3 | ax-mp | ⊢ X 𝑥  ∈  𝐴 𝐵  ⊆  ( ∪  𝑥  ∈  𝐴 𝐵  ↑m  𝐴 ) |