| Step | Hyp | Ref | Expression | 
						
							| 1 |  | sadval.a |  | 
						
							| 2 |  | sadval.b |  | 
						
							| 3 |  | sadval.c |  | 
						
							| 4 |  | nn0ex |  | 
						
							| 5 | 4 | elpw2 |  | 
						
							| 6 | 1 5 | sylibr |  | 
						
							| 7 | 4 | elpw2 |  | 
						
							| 8 | 2 7 | sylibr |  | 
						
							| 9 |  | simpl |  | 
						
							| 10 | 9 | eleq2d |  | 
						
							| 11 |  | simpr |  | 
						
							| 12 | 11 | eleq2d |  | 
						
							| 13 |  | simp1l |  | 
						
							| 14 | 13 | eleq2d |  | 
						
							| 15 |  | simp1r |  | 
						
							| 16 | 15 | eleq2d |  | 
						
							| 17 |  | biidd |  | 
						
							| 18 | 14 16 17 | cadbi123d |  | 
						
							| 19 | 18 | ifbid |  | 
						
							| 20 | 19 | mpoeq3dva |  | 
						
							| 21 | 20 | seqeq2d |  | 
						
							| 22 | 21 3 | eqtr4di |  | 
						
							| 23 | 22 | fveq1d |  | 
						
							| 24 | 23 | eleq2d |  | 
						
							| 25 | 10 12 24 | hadbi123d |  | 
						
							| 26 | 25 | rabbidv |  | 
						
							| 27 |  | df-sad |  | 
						
							| 28 | 4 | rabex |  | 
						
							| 29 | 26 27 28 | ovmpoa |  | 
						
							| 30 | 6 8 29 | syl2anc |  |