| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simpcntrab.a |  | 
						
							| 2 |  | simpcntrab.b |  | 
						
							| 3 |  | simpcntrab.c |  | 
						
							| 4 |  | simpcntrab.d |  | 
						
							| 5 | 4 | simpggrpd |  | 
						
							| 6 | 3 | cntrnsg |  | 
						
							| 7 | 5 6 | syl |  | 
						
							| 8 | 1 2 4 7 | simpgnsgeqd |  | 
						
							| 9 | 8 | ancli |  | 
						
							| 10 |  | andi |  | 
						
							| 11 | 10 | biimpi |  | 
						
							| 12 |  | simpr |  | 
						
							| 13 | 12 | orim1i |  | 
						
							| 14 |  | oveq2 |  | 
						
							| 15 | 3 | oveq2i |  | 
						
							| 16 | 14 15 | eqtr3di |  | 
						
							| 17 | 16 | adantl |  | 
						
							| 18 | 1 | ressid |  | 
						
							| 19 | 5 18 | syl |  | 
						
							| 20 | 19 | adantr |  | 
						
							| 21 | 17 20 | eqtr3d |  | 
						
							| 22 |  | eqid |  | 
						
							| 23 | 22 | cntrabl |  | 
						
							| 24 | 5 23 | syl |  | 
						
							| 25 | 24 | adantr |  | 
						
							| 26 | 21 25 | eqeltrrd |  | 
						
							| 27 | 26 | orim2i |  | 
						
							| 28 | 9 11 13 27 | 4syl |  |