| Step | Hyp | Ref | Expression | 
						
							| 1 |  | lpival.p |  | 
						
							| 2 |  | lpival.k |  | 
						
							| 3 |  | lpival.b |  | 
						
							| 4 |  | fveq2 |  | 
						
							| 5 |  | fveq2 |  | 
						
							| 6 | 5 | fveq1d |  | 
						
							| 7 | 6 | sneqd |  | 
						
							| 8 | 4 7 | iuneq12d |  | 
						
							| 9 |  | df-lpidl |  | 
						
							| 10 |  | fvex |  | 
						
							| 11 | 10 | rnex |  | 
						
							| 12 |  | p0ex |  | 
						
							| 13 | 11 12 | unex |  | 
						
							| 14 |  | iunss |  | 
						
							| 15 |  | fvrn0 |  | 
						
							| 16 |  | snssi |  | 
						
							| 17 | 15 16 | ax-mp |  | 
						
							| 18 | 17 | a1i |  | 
						
							| 19 | 14 18 | mprgbir |  | 
						
							| 20 | 13 19 | ssexi |  | 
						
							| 21 | 8 9 20 | fvmpt |  | 
						
							| 22 |  | iuneq1 |  | 
						
							| 23 | 3 22 | ax-mp |  | 
						
							| 24 | 2 | fveq1i |  | 
						
							| 25 | 24 | sneqi |  | 
						
							| 26 | 25 | a1i |  | 
						
							| 27 | 26 | iuneq2i |  | 
						
							| 28 | 23 27 | eqtri |  | 
						
							| 29 | 21 1 28 | 3eqtr4g |  |