Metamath Proof Explorer
		
		
		
		Description:  Points in the structure product are functions; use this with dffn5 to establish equalities.  (Contributed by Stefan O'Rear, 10-Jan-2015)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypotheses | prdsbasmpt.y | ⊢ 𝑌  =  ( 𝑆 Xs 𝑅 ) | 
					
						|  |  | prdsbasmpt.b | ⊢ 𝐵  =  ( Base ‘ 𝑌 ) | 
					
						|  |  | prdsbasmpt.s | ⊢ ( 𝜑  →  𝑆  ∈  𝑉 ) | 
					
						|  |  | prdsbasmpt.i | ⊢ ( 𝜑  →  𝐼  ∈  𝑊 ) | 
					
						|  |  | prdsbasmpt.r | ⊢ ( 𝜑  →  𝑅  Fn  𝐼 ) | 
					
						|  |  | prdsbasmpt.t | ⊢ ( 𝜑  →  𝑇  ∈  𝐵 ) | 
				
					|  | Assertion | prdsbasfn | ⊢  ( 𝜑  →  𝑇  Fn  𝐼 ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | prdsbasmpt.y | ⊢ 𝑌  =  ( 𝑆 Xs 𝑅 ) | 
						
							| 2 |  | prdsbasmpt.b | ⊢ 𝐵  =  ( Base ‘ 𝑌 ) | 
						
							| 3 |  | prdsbasmpt.s | ⊢ ( 𝜑  →  𝑆  ∈  𝑉 ) | 
						
							| 4 |  | prdsbasmpt.i | ⊢ ( 𝜑  →  𝐼  ∈  𝑊 ) | 
						
							| 5 |  | prdsbasmpt.r | ⊢ ( 𝜑  →  𝑅  Fn  𝐼 ) | 
						
							| 6 |  | prdsbasmpt.t | ⊢ ( 𝜑  →  𝑇  ∈  𝐵 ) | 
						
							| 7 | 1 2 3 4 5 | prdsbas2 | ⊢ ( 𝜑  →  𝐵  =  X 𝑥  ∈  𝐼 ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) | 
						
							| 8 | 6 7 | eleqtrd | ⊢ ( 𝜑  →  𝑇  ∈  X 𝑥  ∈  𝐼 ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) | 
						
							| 9 |  | ixpfn | ⊢ ( 𝑇  ∈  X 𝑥  ∈  𝐼 ( Base ‘ ( 𝑅 ‘ 𝑥 ) )  →  𝑇  Fn  𝐼 ) | 
						
							| 10 | 8 9 | syl | ⊢ ( 𝜑  →  𝑇  Fn  𝐼 ) |