Database  
				BASIC LINEAR ALGEBRA  
				Abstract multivariate polynomials  
				Definition and basic properties  
				opsrmulr  
			 
				
		 
		 Metamath Proof Explorer 
		
			
		 
		 
		
		Description:   The multiplication operation of the ordered power series structure.
       (Contributed by Mario Carneiro , 8-Feb-2015)   (Revised by Mario
       Carneiro , 30-Aug-2015)   (Revised by AV , 1-Nov-2024) 
		
			
				
					 
					 
					Ref 
					Expression 
				 
					
						 
						Hypotheses 
						opsrbas.s  
						⊢  𝑆   =  ( 𝐼   mPwSer  𝑅  )  
					 
					
						 
						 
						opsrbas.o  
						⊢  𝑂   =  ( ( 𝐼   ordPwSer  𝑅  ) ‘ 𝑇  )  
					 
					
						 
						 
						opsrbas.t  
						⊢  ( 𝜑   →  𝑇   ⊆  ( 𝐼   ×  𝐼  ) )  
					 
				
					 
					Assertion 
					opsrmulr  
					⊢   ( 𝜑   →  ( .r  ‘ 𝑆  )  =  ( .r  ‘ 𝑂  ) )  
				 
			
		 
		 
			
				Proof 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							1  
							
								
							 
							opsrbas.s  
							⊢  𝑆   =  ( 𝐼   mPwSer  𝑅  )  
						 
						
							2  
							
								
							 
							opsrbas.o  
							⊢  𝑂   =  ( ( 𝐼   ordPwSer  𝑅  ) ‘ 𝑇  )  
						 
						
							3  
							
								
							 
							opsrbas.t  
							⊢  ( 𝜑   →  𝑇   ⊆  ( 𝐼   ×  𝐼  ) )  
						 
						
							4  
							
								
							 
							mulridx  
							⊢  .r   =  Slot  ( .r  ‘ ndx )  
						 
						
							5  
							
								
							 
							plendxnmulrndx  
							⊢  ( le ‘ ndx )  ≠  ( .r  ‘ ndx )  
						 
						
							6  
							
								5 
							 
							necomi  
							⊢  ( .r  ‘ ndx )  ≠  ( le ‘ ndx )  
						 
						
							7  
							
								1  2  3  4  6 
							 
							opsrbaslem  
							⊢  ( 𝜑   →  ( .r  ‘ 𝑆  )  =  ( .r  ‘ 𝑂  ) )