Database REAL AND COMPLEX NUMBERS Construction and axiomatization of real and complex numbers Real and complex number postulates restated as axioms ax-pre-ltadd  
				
		 
		
			
		 
		Description:   Ordering property of addition on reals.  Axiom 20 of 22 for real and
     complex numbers, justified by Theorem axpre-ltadd  .  Normally new proofs
     would use axltadd  .  (New usage is discouraged.)   (Contributed by NM , 13-Oct-2005) 
		
			
				
					Ref 
					Expression 
				 
				
					Assertion 
					ax-pre-ltadd ⊢   ( ( 𝐴   ∈  ℝ  ∧  𝐵   ∈  ℝ  ∧  𝐶   ∈  ℝ )  →  ( 𝐴   <ℝ   𝐵   →  ( 𝐶   +  𝐴  )  <ℝ   ( 𝐶   +  𝐵  ) ) )  
			
		 
		
				Detailed syntax breakdown 
				
					
						Step 
						Hyp 
						Ref 
						Expression 
					 
						
							0 
								
							 
							cA ⊢  𝐴   
						
							1 
								
							 
							cr ⊢  ℝ  
						
							2 
								0  1 
							 
							wcel ⊢  𝐴   ∈  ℝ  
						
							3 
								
							 
							cB ⊢  𝐵   
						
							4 
								3  1 
							 
							wcel ⊢  𝐵   ∈  ℝ  
						
							5 
								
							 
							cC ⊢  𝐶   
						
							6 
								5  1 
							 
							wcel ⊢  𝐶   ∈  ℝ  
						
							7 
								2  4  6 
							 
							w3a ⊢  ( 𝐴   ∈  ℝ  ∧  𝐵   ∈  ℝ  ∧  𝐶   ∈  ℝ )  
						
							8 
								
							 
							cltrr ⊢   <ℝ    
						
							9 
								0  3  8 
							 
							wbr ⊢  𝐴   <ℝ   𝐵   
						
							10 
								
							 
							caddc ⊢   +   
						
							11 
								5  0  10 
							 
							co ⊢  ( 𝐶   +  𝐴  )  
						
							12 
								5  3  10 
							 
							co ⊢  ( 𝐶   +  𝐵  )  
						
							13 
								11  12  8 
							 
							wbr ⊢  ( 𝐶   +  𝐴  )  <ℝ   ( 𝐶   +  𝐵  )  
						
							14 
								9  13 
							 
							wi ⊢  ( 𝐴   <ℝ   𝐵   →  ( 𝐶   +  𝐴  )  <ℝ   ( 𝐶   +  𝐵  ) )  
						
							15 
								7  14 
							 
							wi ⊢  ( ( 𝐴   ∈  ℝ  ∧  𝐵   ∈  ℝ  ∧  𝐶   ∈  ℝ )  →  ( 𝐴   <ℝ   𝐵   →  ( 𝐶   +  𝐴  )  <ℝ   ( 𝐶   +  𝐵  ) ) )