| Step | Hyp | Ref | Expression | 
						
							| 1 |  | shftfval.1 |  | 
						
							| 2 |  | ovex |  | 
						
							| 3 |  | vex |  | 
						
							| 4 | 2 3 | breldm |  | 
						
							| 5 |  | npcan |  | 
						
							| 6 | 5 | eqcomd |  | 
						
							| 7 | 6 | ancoms |  | 
						
							| 8 |  | oveq1 |  | 
						
							| 9 | 8 | rspceeqv |  | 
						
							| 10 | 4 7 9 | syl2anr |  | 
						
							| 11 |  | vex |  | 
						
							| 12 |  | eqeq1 |  | 
						
							| 13 | 12 | rexbidv |  | 
						
							| 14 | 11 13 | elab |  | 
						
							| 15 | 10 14 | sylibr |  | 
						
							| 16 | 2 3 | brelrn |  | 
						
							| 17 | 16 | adantl |  | 
						
							| 18 | 15 17 | jca |  | 
						
							| 19 | 18 | expl |  | 
						
							| 20 | 19 | ssopab2dv |  | 
						
							| 21 |  | df-xp |  | 
						
							| 22 | 20 21 | sseqtrrdi |  | 
						
							| 23 | 1 | dmex |  | 
						
							| 24 | 23 | abrexex |  | 
						
							| 25 | 1 | rnex |  | 
						
							| 26 | 24 25 | xpex |  | 
						
							| 27 |  | ssexg |  | 
						
							| 28 | 22 26 27 | sylancl |  | 
						
							| 29 |  | breq |  | 
						
							| 30 | 29 | anbi2d |  | 
						
							| 31 | 30 | opabbidv |  | 
						
							| 32 |  | oveq2 |  | 
						
							| 33 | 32 | breq1d |  | 
						
							| 34 | 33 | anbi2d |  | 
						
							| 35 | 34 | opabbidv |  | 
						
							| 36 |  | df-shft |  | 
						
							| 37 | 31 35 36 | ovmpog |  | 
						
							| 38 | 1 37 | mp3an1 |  | 
						
							| 39 | 28 38 | mpdan |  |