Database ZF (ZERMELO-FRAENKEL) SET THEORY ZF Set Theory - add the Axiom of Union Finitely supported functions fsuppsssuppgd  
				
		 
		
			
		 
		Description:   If the support of a function is a subset of a finite support, it is
       finite.  Deduction associated with fsuppsssupp  .  (Contributed by SN , 6-Mar-2025) 
		
			
				
					Ref 
					Expression 
				 
					
						Hypotheses 
						fsuppsssuppgd.g ⊢  ( 𝜑   →  𝐺   ∈  𝑉  )  
					
						fsuppsssuppgd.z ⊢  ( 𝜑   →  𝑍   ∈  𝑊  )  
					
						fsuppsssuppgd.1 ⊢  ( 𝜑   →  Fun  𝐺  )  
					
						fsuppsssuppgd.2 ⊢  ( 𝜑   →  𝐹   finSupp  𝑂  )  
					
						fsuppsssuppgd.3 ⊢  ( 𝜑   →  ( 𝐺   supp  𝑍  )  ⊆  ( 𝐹   supp  𝑂  ) )  
				
					Assertion 
					fsuppsssuppgd ⊢   ( 𝜑   →  𝐺   finSupp  𝑍  )  
			
		 
		
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1 
								
							 
							fsuppsssuppgd.g ⊢  ( 𝜑   →  𝐺   ∈  𝑉  )  
						
							2 
								
							 
							fsuppsssuppgd.z ⊢  ( 𝜑   →  𝑍   ∈  𝑊  )  
						
							3 
								
							 
							fsuppsssuppgd.1 ⊢  ( 𝜑   →  Fun  𝐺  )  
						
							4 
								
							 
							fsuppsssuppgd.2 ⊢  ( 𝜑   →  𝐹   finSupp  𝑂  )  
						
							5 
								
							 
							fsuppsssuppgd.3 ⊢  ( 𝜑   →  ( 𝐺   supp  𝑍  )  ⊆  ( 𝐹   supp  𝑂  ) )  
						
							6 
								4 
							 
							fsuppimpd ⊢  ( 𝜑   →  ( 𝐹   supp  𝑂  )  ∈  Fin )  
						
							7 
								
							 
							suppssfifsupp ⊢  ( ( ( 𝐺   ∈  𝑉   ∧  Fun  𝐺   ∧  𝑍   ∈  𝑊  )  ∧  ( ( 𝐹   supp  𝑂  )  ∈  Fin  ∧  ( 𝐺   supp  𝑍  )  ⊆  ( 𝐹   supp  𝑂  ) ) )  →  𝐺   finSupp  𝑍  )  
						
							8 
								1  3  2  6  5  7 
							 
							syl32anc ⊢  ( 𝜑   →  𝐺   finSupp  𝑍  )