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  class  A    
						
							1 
								
							 
							cr  class   ℝ     
						
							2 
								0  1 
							 
							wcel  wff   A  ∈   ℝ       
						
							3 
								
							 
							cB  class  B    
						
							4 
								3  1 
							 
							wcel  wff   B  ∈   ℝ       
						
							5 
								
							 
							cC  class  C    
						
							6 
								5  1 
							 
							wcel  wff   C  ∈   ℝ       
						
							7 
								2  4  6 
							 
							w3a  wff    A  ∈   ℝ     ∧   B  ∈   ℝ     ∧   C  ∈   ℝ         
						
							8 
								
							 
							cltrr  class  <  ℝ    
						
							9 
								0  3  8 
							 
							wbr  wff   A  <  ℝ B      
						
							10 
								
							 
							caddc  class  +    
						
							11 
								5  0  10 
							 
							co  class  C  +  A    
						
							12 
								5  3  10 
							 
							co  class  C  +  B    
						
							13 
								11  12  8 
							 
							wbr  wff   C  +  A <  ℝ C  +  B     
						
							14 
								9  13 
							 
							wi  wff    A  <  ℝ B    →   C  +  A <  ℝ C  +  B       
						
							15 
								7  14 
							 
							wi  wff     A  ∈   ℝ     ∧   B  ∈   ℝ     ∧   C  ∈   ℝ      →    A  <  ℝ B    →   C  +  A <  ℝ C  +  B