| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 2wlkd.p |  |-  P = <" A B C "> | 
						
							| 2 |  | 2wlkd.f |  |-  F = <" J K "> | 
						
							| 3 |  | 2wlkd.s |  |-  ( ph -> ( A e. V /\ B e. V /\ C e. V ) ) | 
						
							| 4 |  | 2wlkd.n |  |-  ( ph -> ( A =/= B /\ B =/= C ) ) | 
						
							| 5 | 1 2 3 | 2wlkdlem3 |  |-  ( ph -> ( ( P ` 0 ) = A /\ ( P ` 1 ) = B /\ ( P ` 2 ) = C ) ) | 
						
							| 6 |  | simp1 |  |-  ( ( ( P ` 0 ) = A /\ ( P ` 1 ) = B /\ ( P ` 2 ) = C ) -> ( P ` 0 ) = A ) | 
						
							| 7 |  | simp2 |  |-  ( ( ( P ` 0 ) = A /\ ( P ` 1 ) = B /\ ( P ` 2 ) = C ) -> ( P ` 1 ) = B ) | 
						
							| 8 | 6 7 | neeq12d |  |-  ( ( ( P ` 0 ) = A /\ ( P ` 1 ) = B /\ ( P ` 2 ) = C ) -> ( ( P ` 0 ) =/= ( P ` 1 ) <-> A =/= B ) ) | 
						
							| 9 |  | simp3 |  |-  ( ( ( P ` 0 ) = A /\ ( P ` 1 ) = B /\ ( P ` 2 ) = C ) -> ( P ` 2 ) = C ) | 
						
							| 10 | 7 9 | neeq12d |  |-  ( ( ( P ` 0 ) = A /\ ( P ` 1 ) = B /\ ( P ` 2 ) = C ) -> ( ( P ` 1 ) =/= ( P ` 2 ) <-> B =/= C ) ) | 
						
							| 11 | 8 10 | anbi12d |  |-  ( ( ( P ` 0 ) = A /\ ( P ` 1 ) = B /\ ( P ` 2 ) = C ) -> ( ( ( P ` 0 ) =/= ( P ` 1 ) /\ ( P ` 1 ) =/= ( P ` 2 ) ) <-> ( A =/= B /\ B =/= C ) ) ) | 
						
							| 12 | 11 | bicomd |  |-  ( ( ( P ` 0 ) = A /\ ( P ` 1 ) = B /\ ( P ` 2 ) = C ) -> ( ( A =/= B /\ B =/= C ) <-> ( ( P ` 0 ) =/= ( P ` 1 ) /\ ( P ` 1 ) =/= ( P ` 2 ) ) ) ) | 
						
							| 13 | 5 12 | syl |  |-  ( ph -> ( ( A =/= B /\ B =/= C ) <-> ( ( P ` 0 ) =/= ( P ` 1 ) /\ ( P ` 1 ) =/= ( P ` 2 ) ) ) ) | 
						
							| 14 | 4 13 | mpbid |  |-  ( ph -> ( ( P ` 0 ) =/= ( P ` 1 ) /\ ( P ` 1 ) =/= ( P ` 2 ) ) ) | 
						
							| 15 | 1 2 | 2wlkdlem2 |  |-  ( 0 ..^ ( # ` F ) ) = { 0 , 1 } | 
						
							| 16 | 15 | raleqi |  |-  ( A. k e. ( 0 ..^ ( # ` F ) ) ( P ` k ) =/= ( P ` ( k + 1 ) ) <-> A. k e. { 0 , 1 } ( P ` k ) =/= ( P ` ( k + 1 ) ) ) | 
						
							| 17 |  | c0ex |  |-  0 e. _V | 
						
							| 18 |  | 1ex |  |-  1 e. _V | 
						
							| 19 |  | fveq2 |  |-  ( k = 0 -> ( P ` k ) = ( P ` 0 ) ) | 
						
							| 20 |  | fv0p1e1 |  |-  ( k = 0 -> ( P ` ( k + 1 ) ) = ( P ` 1 ) ) | 
						
							| 21 | 19 20 | neeq12d |  |-  ( k = 0 -> ( ( P ` k ) =/= ( P ` ( k + 1 ) ) <-> ( P ` 0 ) =/= ( P ` 1 ) ) ) | 
						
							| 22 |  | fveq2 |  |-  ( k = 1 -> ( P ` k ) = ( P ` 1 ) ) | 
						
							| 23 |  | oveq1 |  |-  ( k = 1 -> ( k + 1 ) = ( 1 + 1 ) ) | 
						
							| 24 |  | 1p1e2 |  |-  ( 1 + 1 ) = 2 | 
						
							| 25 | 23 24 | eqtrdi |  |-  ( k = 1 -> ( k + 1 ) = 2 ) | 
						
							| 26 | 25 | fveq2d |  |-  ( k = 1 -> ( P ` ( k + 1 ) ) = ( P ` 2 ) ) | 
						
							| 27 | 22 26 | neeq12d |  |-  ( k = 1 -> ( ( P ` k ) =/= ( P ` ( k + 1 ) ) <-> ( P ` 1 ) =/= ( P ` 2 ) ) ) | 
						
							| 28 | 17 18 21 27 | ralpr |  |-  ( A. k e. { 0 , 1 } ( P ` k ) =/= ( P ` ( k + 1 ) ) <-> ( ( P ` 0 ) =/= ( P ` 1 ) /\ ( P ` 1 ) =/= ( P ` 2 ) ) ) | 
						
							| 29 | 16 28 | bitri |  |-  ( A. k e. ( 0 ..^ ( # ` F ) ) ( P ` k ) =/= ( P ` ( k + 1 ) ) <-> ( ( P ` 0 ) =/= ( P ` 1 ) /\ ( P ` 1 ) =/= ( P ` 2 ) ) ) | 
						
							| 30 | 14 29 | sylibr |  |-  ( ph -> A. k e. ( 0 ..^ ( # ` F ) ) ( P ` k ) =/= ( P ` ( k + 1 ) ) ) |