Metamath Proof Explorer
		
		
		
		Description:  Distribution of negative over addition.  (Contributed by NM, 24-Aug-2006)
     (New usage is discouraged.)
		
			
				
					|  |  | Ref | Expression | 
				
					|  | Assertion | honegdi | ⊢  ( ( 𝑇 :  ℋ ⟶  ℋ  ∧  𝑈 :  ℋ ⟶  ℋ )  →  ( - 1  ·op  ( 𝑇  +op  𝑈 ) )  =  ( ( - 1  ·op  𝑇 )  +op  ( - 1  ·op  𝑈 ) ) ) | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | neg1cn | ⊢ - 1  ∈  ℂ | 
						
							| 2 |  | hoadddi | ⊢ ( ( - 1  ∈  ℂ  ∧  𝑇 :  ℋ ⟶  ℋ  ∧  𝑈 :  ℋ ⟶  ℋ )  →  ( - 1  ·op  ( 𝑇  +op  𝑈 ) )  =  ( ( - 1  ·op  𝑇 )  +op  ( - 1  ·op  𝑈 ) ) ) | 
						
							| 3 | 1 2 | mp3an1 | ⊢ ( ( 𝑇 :  ℋ ⟶  ℋ  ∧  𝑈 :  ℋ ⟶  ℋ )  →  ( - 1  ·op  ( 𝑇  +op  𝑈 ) )  =  ( ( - 1  ·op  𝑇 )  +op  ( - 1  ·op  𝑈 ) ) ) |