| Step | Hyp | Ref | Expression | 
						
							| 1 |  | clwlkclwwlklem2.f |  |-  F = ( x e. ( 0 ..^ ( ( # ` P ) - 1 ) ) |-> if ( x < ( ( # ` P ) - 2 ) , ( `' E ` { ( P ` x ) , ( P ` ( x + 1 ) ) } ) , ( `' E ` { ( P ` x ) , ( P ` 0 ) } ) ) ) | 
						
							| 2 |  | breq1 |  |-  ( x = I -> ( x < ( ( # ` P ) - 2 ) <-> I < ( ( # ` P ) - 2 ) ) ) | 
						
							| 3 |  | fveq2 |  |-  ( x = I -> ( P ` x ) = ( P ` I ) ) | 
						
							| 4 |  | fvoveq1 |  |-  ( x = I -> ( P ` ( x + 1 ) ) = ( P ` ( I + 1 ) ) ) | 
						
							| 5 | 3 4 | preq12d |  |-  ( x = I -> { ( P ` x ) , ( P ` ( x + 1 ) ) } = { ( P ` I ) , ( P ` ( I + 1 ) ) } ) | 
						
							| 6 | 5 | fveq2d |  |-  ( x = I -> ( `' E ` { ( P ` x ) , ( P ` ( x + 1 ) ) } ) = ( `' E ` { ( P ` I ) , ( P ` ( I + 1 ) ) } ) ) | 
						
							| 7 | 3 | preq1d |  |-  ( x = I -> { ( P ` x ) , ( P ` 0 ) } = { ( P ` I ) , ( P ` 0 ) } ) | 
						
							| 8 | 7 | fveq2d |  |-  ( x = I -> ( `' E ` { ( P ` x ) , ( P ` 0 ) } ) = ( `' E ` { ( P ` I ) , ( P ` 0 ) } ) ) | 
						
							| 9 | 2 6 8 | ifbieq12d |  |-  ( x = I -> if ( x < ( ( # ` P ) - 2 ) , ( `' E ` { ( P ` x ) , ( P ` ( x + 1 ) ) } ) , ( `' E ` { ( P ` x ) , ( P ` 0 ) } ) ) = if ( I < ( ( # ` P ) - 2 ) , ( `' E ` { ( P ` I ) , ( P ` ( I + 1 ) ) } ) , ( `' E ` { ( P ` I ) , ( P ` 0 ) } ) ) ) | 
						
							| 10 |  | elfzolt2 |  |-  ( I e. ( 0 ..^ ( ( # ` P ) - 2 ) ) -> I < ( ( # ` P ) - 2 ) ) | 
						
							| 11 | 10 | adantl |  |-  ( ( ( # ` P ) e. NN0 /\ I e. ( 0 ..^ ( ( # ` P ) - 2 ) ) ) -> I < ( ( # ` P ) - 2 ) ) | 
						
							| 12 | 11 | iftrued |  |-  ( ( ( # ` P ) e. NN0 /\ I e. ( 0 ..^ ( ( # ` P ) - 2 ) ) ) -> if ( I < ( ( # ` P ) - 2 ) , ( `' E ` { ( P ` I ) , ( P ` ( I + 1 ) ) } ) , ( `' E ` { ( P ` I ) , ( P ` 0 ) } ) ) = ( `' E ` { ( P ` I ) , ( P ` ( I + 1 ) ) } ) ) | 
						
							| 13 | 9 12 | sylan9eqr |  |-  ( ( ( ( # ` P ) e. NN0 /\ I e. ( 0 ..^ ( ( # ` P ) - 2 ) ) ) /\ x = I ) -> if ( x < ( ( # ` P ) - 2 ) , ( `' E ` { ( P ` x ) , ( P ` ( x + 1 ) ) } ) , ( `' E ` { ( P ` x ) , ( P ` 0 ) } ) ) = ( `' E ` { ( P ` I ) , ( P ` ( I + 1 ) ) } ) ) | 
						
							| 14 |  | nn0z |  |-  ( ( # ` P ) e. NN0 -> ( # ` P ) e. ZZ ) | 
						
							| 15 |  | 2z |  |-  2 e. ZZ | 
						
							| 16 | 15 | a1i |  |-  ( ( # ` P ) e. NN0 -> 2 e. ZZ ) | 
						
							| 17 | 14 16 | zsubcld |  |-  ( ( # ` P ) e. NN0 -> ( ( # ` P ) - 2 ) e. ZZ ) | 
						
							| 18 |  | peano2zm |  |-  ( ( # ` P ) e. ZZ -> ( ( # ` P ) - 1 ) e. ZZ ) | 
						
							| 19 | 14 18 | syl |  |-  ( ( # ` P ) e. NN0 -> ( ( # ` P ) - 1 ) e. ZZ ) | 
						
							| 20 |  | 1red |  |-  ( ( # ` P ) e. NN0 -> 1 e. RR ) | 
						
							| 21 |  | 2re |  |-  2 e. RR | 
						
							| 22 | 21 | a1i |  |-  ( ( # ` P ) e. NN0 -> 2 e. RR ) | 
						
							| 23 |  | nn0re |  |-  ( ( # ` P ) e. NN0 -> ( # ` P ) e. RR ) | 
						
							| 24 |  | 1le2 |  |-  1 <_ 2 | 
						
							| 25 | 24 | a1i |  |-  ( ( # ` P ) e. NN0 -> 1 <_ 2 ) | 
						
							| 26 | 20 22 23 25 | lesub2dd |  |-  ( ( # ` P ) e. NN0 -> ( ( # ` P ) - 2 ) <_ ( ( # ` P ) - 1 ) ) | 
						
							| 27 |  | eluz2 |  |-  ( ( ( # ` P ) - 1 ) e. ( ZZ>= ` ( ( # ` P ) - 2 ) ) <-> ( ( ( # ` P ) - 2 ) e. ZZ /\ ( ( # ` P ) - 1 ) e. ZZ /\ ( ( # ` P ) - 2 ) <_ ( ( # ` P ) - 1 ) ) ) | 
						
							| 28 | 17 19 26 27 | syl3anbrc |  |-  ( ( # ` P ) e. NN0 -> ( ( # ` P ) - 1 ) e. ( ZZ>= ` ( ( # ` P ) - 2 ) ) ) | 
						
							| 29 |  | fzoss2 |  |-  ( ( ( # ` P ) - 1 ) e. ( ZZ>= ` ( ( # ` P ) - 2 ) ) -> ( 0 ..^ ( ( # ` P ) - 2 ) ) C_ ( 0 ..^ ( ( # ` P ) - 1 ) ) ) | 
						
							| 30 | 28 29 | syl |  |-  ( ( # ` P ) e. NN0 -> ( 0 ..^ ( ( # ` P ) - 2 ) ) C_ ( 0 ..^ ( ( # ` P ) - 1 ) ) ) | 
						
							| 31 | 30 | sselda |  |-  ( ( ( # ` P ) e. NN0 /\ I e. ( 0 ..^ ( ( # ` P ) - 2 ) ) ) -> I e. ( 0 ..^ ( ( # ` P ) - 1 ) ) ) | 
						
							| 32 |  | fvexd |  |-  ( ( ( # ` P ) e. NN0 /\ I e. ( 0 ..^ ( ( # ` P ) - 2 ) ) ) -> ( `' E ` { ( P ` I ) , ( P ` ( I + 1 ) ) } ) e. _V ) | 
						
							| 33 | 1 13 31 32 | fvmptd2 |  |-  ( ( ( # ` P ) e. NN0 /\ I e. ( 0 ..^ ( ( # ` P ) - 2 ) ) ) -> ( F ` I ) = ( `' E ` { ( P ` I ) , ( P ` ( I + 1 ) ) } ) ) |