| Step | Hyp | Ref | Expression | 
						
							| 1 |  | gcdabs |  | 
						
							| 2 | 1 | 3adant3 |  | 
						
							| 3 | 2 | eqcomd |  | 
						
							| 4 | 3 | oveq1d |  | 
						
							| 5 |  | nn0abscl |  | 
						
							| 6 |  | nn0abscl |  | 
						
							| 7 |  | id |  | 
						
							| 8 |  | nn0expgcd |  | 
						
							| 9 | 5 6 7 8 | syl3an |  | 
						
							| 10 |  | zcn |  | 
						
							| 11 | 10 | 3ad2ant1 |  | 
						
							| 12 |  | simp3 |  | 
						
							| 13 | 11 12 | absexpd |  | 
						
							| 14 | 13 | eqcomd |  | 
						
							| 15 |  | zcn |  | 
						
							| 16 | 15 | 3ad2ant2 |  | 
						
							| 17 | 16 12 | absexpd |  | 
						
							| 18 | 17 | eqcomd |  | 
						
							| 19 | 14 18 | oveq12d |  | 
						
							| 20 |  | zexpcl |  | 
						
							| 21 | 20 | 3adant2 |  | 
						
							| 22 |  | zexpcl |  | 
						
							| 23 | 22 | 3adant1 |  | 
						
							| 24 |  | gcdabs |  | 
						
							| 25 | 21 23 24 | syl2anc |  | 
						
							| 26 | 19 25 | eqtrd |  | 
						
							| 27 | 4 9 26 | 3eqtrd |  |