| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elfz2 |  | 
						
							| 2 |  | 3simpc |  | 
						
							| 3 | 2 | adantr |  | 
						
							| 4 | 1 3 | sylbi |  | 
						
							| 5 | 4 | anim2i |  | 
						
							| 6 |  | simpl |  | 
						
							| 7 | 6 | anim2i |  | 
						
							| 8 | 7 | ancomd |  | 
						
							| 9 |  | zsubcl |  | 
						
							| 10 | 8 9 | syl |  | 
						
							| 11 | 6 | adantl |  | 
						
							| 12 |  | simprr |  | 
						
							| 13 | 10 11 12 | 3jca |  | 
						
							| 14 | 5 13 | syl |  | 
						
							| 15 | 14 | 3adant3 |  | 
						
							| 16 |  | elfzel2 |  | 
						
							| 17 | 16 | zred |  | 
						
							| 18 | 17 | adantl |  | 
						
							| 19 |  | zre |  | 
						
							| 20 | 19 | adantr |  | 
						
							| 21 |  | elfzelz |  | 
						
							| 22 | 21 | zred |  | 
						
							| 23 | 22 | adantl |  | 
						
							| 24 | 18 20 23 | 3jca |  | 
						
							| 25 |  | simp1 |  | 
						
							| 26 |  | readdcl |  | 
						
							| 27 | 26 | 3adant1 |  | 
						
							| 28 |  | ltle |  | 
						
							| 29 | 25 27 28 | syl2anc |  | 
						
							| 30 |  | lesubadd2 |  | 
						
							| 31 | 29 30 | sylibrd |  | 
						
							| 32 | 24 31 | syl |  | 
						
							| 33 | 32 | 3impia |  | 
						
							| 34 |  | elfzle2 |  | 
						
							| 35 | 34 | 3ad2ant2 |  | 
						
							| 36 | 15 33 35 | jca32 |  | 
						
							| 37 |  | elfz2 |  | 
						
							| 38 | 36 37 | sylibr |  |