| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ang.1 |  | 
						
							| 2 |  | simp1l |  | 
						
							| 3 |  | 1cnd |  | 
						
							| 4 |  | simp2l |  | 
						
							| 5 |  | simp1r |  | 
						
							| 6 | 4 2 5 | divcld |  | 
						
							| 7 | 2 3 6 | subdid |  | 
						
							| 8 | 2 | mulridd |  | 
						
							| 9 | 4 2 5 | divcan2d |  | 
						
							| 10 | 8 9 | oveq12d |  | 
						
							| 11 | 7 10 | eqtrd |  | 
						
							| 12 | 11 8 | oveq12d |  | 
						
							| 13 | 3 6 | subcld |  | 
						
							| 14 |  | simp3 |  | 
						
							| 15 | 14 | necomd |  | 
						
							| 16 | 4 2 5 15 | divne1d |  | 
						
							| 17 | 16 | necomd |  | 
						
							| 18 | 3 6 17 | subne0d |  | 
						
							| 19 |  | ax-1ne0 |  | 
						
							| 20 | 19 | a1i |  | 
						
							| 21 | 1 | angcan |  | 
						
							| 22 | 13 18 3 20 2 5 21 | syl222anc |  | 
						
							| 23 | 12 22 | eqtr3d |  | 
						
							| 24 | 2 6 3 | subdid |  | 
						
							| 25 | 9 8 | oveq12d |  | 
						
							| 26 | 24 25 | eqtrd |  | 
						
							| 27 | 9 26 | oveq12d |  | 
						
							| 28 |  | simp2r |  | 
						
							| 29 | 4 2 28 5 | divne0d |  | 
						
							| 30 | 6 3 | subcld |  | 
						
							| 31 | 6 3 16 | subne0d |  | 
						
							| 32 | 1 | angcan |  | 
						
							| 33 | 6 29 30 31 2 5 32 | syl222anc |  | 
						
							| 34 | 27 33 | eqtr3d |  | 
						
							| 35 | 23 34 | oveq12d |  | 
						
							| 36 | 8 9 | oveq12d |  | 
						
							| 37 | 1 | angcan |  | 
						
							| 38 | 3 20 6 29 2 5 37 | syl222anc |  | 
						
							| 39 | 36 38 | eqtr3d |  | 
						
							| 40 | 35 39 | oveq12d |  | 
						
							| 41 | 1 | ang180lem4 |  | 
						
							| 42 | 6 29 16 41 | syl3anc |  | 
						
							| 43 | 40 42 | eqeltrd |  |