| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 2wlkd.p |  | 
						
							| 2 |  | 2wlkd.f |  | 
						
							| 3 |  | 2wlkd.s |  | 
						
							| 4 |  | 2wlkd.n |  | 
						
							| 5 |  | 2wlkd.e |  | 
						
							| 6 | 1 2 3 4 5 | 2wlkdlem9 |  | 
						
							| 7 | 1 2 3 | 2wlkdlem3 |  | 
						
							| 8 |  | preq12 |  | 
						
							| 9 | 8 | 3adant3 |  | 
						
							| 10 | 9 | sseq1d |  | 
						
							| 11 |  | preq12 |  | 
						
							| 12 | 11 | 3adant1 |  | 
						
							| 13 | 12 | sseq1d |  | 
						
							| 14 | 10 13 | anbi12d |  | 
						
							| 15 | 7 14 | syl |  | 
						
							| 16 | 6 15 | mpbird |  | 
						
							| 17 | 1 2 | 2wlkdlem2 |  | 
						
							| 18 | 17 | raleqi |  | 
						
							| 19 |  | c0ex |  | 
						
							| 20 |  | 1ex |  | 
						
							| 21 |  | fveq2 |  | 
						
							| 22 |  | fv0p1e1 |  | 
						
							| 23 | 21 22 | preq12d |  | 
						
							| 24 |  | 2fveq3 |  | 
						
							| 25 | 23 24 | sseq12d |  | 
						
							| 26 |  | fveq2 |  | 
						
							| 27 |  | oveq1 |  | 
						
							| 28 |  | 1p1e2 |  | 
						
							| 29 | 27 28 | eqtrdi |  | 
						
							| 30 | 29 | fveq2d |  | 
						
							| 31 | 26 30 | preq12d |  | 
						
							| 32 |  | 2fveq3 |  | 
						
							| 33 | 31 32 | sseq12d |  | 
						
							| 34 | 19 20 25 33 | ralpr |  | 
						
							| 35 | 18 34 | bitri |  | 
						
							| 36 | 16 35 | sylibr |  |