| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elfzoel1 |  | 
						
							| 2 | 1 | adantr |  | 
						
							| 3 | 2 | zred |  | 
						
							| 4 |  | elfzoelz |  | 
						
							| 5 | 4 | adantr |  | 
						
							| 6 | 5 | zred |  | 
						
							| 7 |  | simpr |  | 
						
							| 8 | 7 | zred |  | 
						
							| 9 |  | elfzole1 |  | 
						
							| 10 | 9 | adantr |  | 
						
							| 11 | 3 6 8 10 | leadd1dd |  | 
						
							| 12 |  | elfzoel2 |  | 
						
							| 13 | 12 | adantr |  | 
						
							| 14 | 13 | zred |  | 
						
							| 15 |  | elfzolt2 |  | 
						
							| 16 | 15 | adantr |  | 
						
							| 17 | 6 14 8 16 | ltadd1dd |  | 
						
							| 18 |  | zaddcl |  | 
						
							| 19 | 4 18 | sylan |  | 
						
							| 20 |  | zaddcl |  | 
						
							| 21 | 1 20 | sylan |  | 
						
							| 22 |  | zaddcl |  | 
						
							| 23 | 12 22 | sylan |  | 
						
							| 24 |  | elfzo |  | 
						
							| 25 | 19 21 23 24 | syl3anc |  | 
						
							| 26 | 11 17 25 | mpbir2and |  |