Metamath Proof Explorer
		
		
		
		Description:  Commutation of antecedents.  Rotate left.  (Contributed by Jeff Hankins, 28-Jun-2009)  (Proof shortened by Wolf Lammen, 29-Jul-2012)
		
			
				
					|  |  | Ref | Expression | 
					
						|  | Hypothesis | com5.1 |  | 
				
					|  | Assertion | com5l |  | 
			
		
		
			
				Proof
				
					
						| Step | Hyp | Ref | Expression | 
						
							| 1 |  | com5.1 |  | 
						
							| 2 | 1 | com4l |  | 
						
							| 3 | 2 | com45 |  |