| Step | Hyp | Ref | Expression | 
						
							| 1 |  | btwnxfr |  | 
						
							| 2 | 1 | expcomd |  | 
						
							| 3 | 2 | imp |  | 
						
							| 4 |  | cgr3permute4 |  | 
						
							| 5 |  | biid |  | 
						
							| 6 |  | 3anrot |  | 
						
							| 7 |  | 3anrot |  | 
						
							| 8 |  | btwnxfr |  | 
						
							| 9 | 5 6 7 8 | syl3anbr |  | 
						
							| 10 | 9 | expcomd |  | 
						
							| 11 | 4 10 | sylbid |  | 
						
							| 12 | 11 | imp |  | 
						
							| 13 |  | cgr3permute3 |  | 
						
							| 14 |  | 3anrot |  | 
						
							| 15 |  | 3anrot |  | 
						
							| 16 |  | btwnxfr |  | 
						
							| 17 | 5 14 15 16 | syl3anb |  | 
						
							| 18 | 17 | expcomd |  | 
						
							| 19 | 13 18 | sylbid |  | 
						
							| 20 | 19 | imp |  | 
						
							| 21 | 3 12 20 | 3orim123d |  | 
						
							| 22 |  | simp1 |  | 
						
							| 23 |  | simp22 |  | 
						
							| 24 |  | simp21 |  | 
						
							| 25 |  | simp23 |  | 
						
							| 26 |  | brcolinear |  | 
						
							| 27 | 22 23 24 25 26 | syl13anc |  | 
						
							| 28 | 27 | adantr |  | 
						
							| 29 |  | simp32 |  | 
						
							| 30 |  | simp31 |  | 
						
							| 31 |  | simp33 |  | 
						
							| 32 |  | brcolinear |  | 
						
							| 33 | 22 29 30 31 32 | syl13anc |  | 
						
							| 34 | 33 | adantr |  | 
						
							| 35 | 21 28 34 | 3imtr4d |  | 
						
							| 36 | 35 | ex |  | 
						
							| 37 | 36 | com23 |  | 
						
							| 38 | 37 | impd |  |