| Step | Hyp | Ref | Expression | 
						
							| 1 |  | axlowdimlem13.1 |  |-  P = ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) | 
						
							| 2 |  | axlowdimlem13.2 |  |-  Q = ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) | 
						
							| 3 |  | 2ne0 |  |-  2 =/= 0 | 
						
							| 4 | 3 | neii |  |-  -. 2 = 0 | 
						
							| 5 |  | eqcom |  |-  ( 2 = 0 <-> 0 = 2 ) | 
						
							| 6 |  | 1pneg1e0 |  |-  ( 1 + -u 1 ) = 0 | 
						
							| 7 | 6 | eqcomi |  |-  0 = ( 1 + -u 1 ) | 
						
							| 8 |  | df-2 |  |-  2 = ( 1 + 1 ) | 
						
							| 9 | 7 8 | eqeq12i |  |-  ( 0 = 2 <-> ( 1 + -u 1 ) = ( 1 + 1 ) ) | 
						
							| 10 |  | ax-1cn |  |-  1 e. CC | 
						
							| 11 |  | neg1cn |  |-  -u 1 e. CC | 
						
							| 12 | 10 11 10 | addcani |  |-  ( ( 1 + -u 1 ) = ( 1 + 1 ) <-> -u 1 = 1 ) | 
						
							| 13 | 5 9 12 | 3bitri |  |-  ( 2 = 0 <-> -u 1 = 1 ) | 
						
							| 14 | 4 13 | mtbi |  |-  -. -u 1 = 1 | 
						
							| 15 | 14 | intnanr |  |-  -. ( -u 1 = 1 /\ 0 = 0 ) | 
						
							| 16 |  | ax-1ne0 |  |-  1 =/= 0 | 
						
							| 17 | 16 | neii |  |-  -. 1 = 0 | 
						
							| 18 |  | negeq0 |  |-  ( 1 e. CC -> ( 1 = 0 <-> -u 1 = 0 ) ) | 
						
							| 19 | 10 18 | ax-mp |  |-  ( 1 = 0 <-> -u 1 = 0 ) | 
						
							| 20 | 17 19 | mtbi |  |-  -. -u 1 = 0 | 
						
							| 21 | 20 | intnanr |  |-  -. ( -u 1 = 0 /\ 0 = 1 ) | 
						
							| 22 | 15 21 | pm3.2ni |  |-  -. ( ( -u 1 = 1 /\ 0 = 0 ) \/ ( -u 1 = 0 /\ 0 = 1 ) ) | 
						
							| 23 |  | negex |  |-  -u 1 e. _V | 
						
							| 24 |  | c0ex |  |-  0 e. _V | 
						
							| 25 |  | 1ex |  |-  1 e. _V | 
						
							| 26 | 23 24 25 24 | preq12b |  |-  ( { -u 1 , 0 } = { 1 , 0 } <-> ( ( -u 1 = 1 /\ 0 = 0 ) \/ ( -u 1 = 0 /\ 0 = 1 ) ) ) | 
						
							| 27 | 22 26 | mtbir |  |-  -. { -u 1 , 0 } = { 1 , 0 } | 
						
							| 28 |  | 3ex |  |-  3 e. _V | 
						
							| 29 | 28 | rnsnop |  |-  ran { <. 3 , -u 1 >. } = { -u 1 } | 
						
							| 30 | 29 | a1i |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ran { <. 3 , -u 1 >. } = { -u 1 } ) | 
						
							| 31 |  | elnnuz |  |-  ( N e. NN <-> N e. ( ZZ>= ` 1 ) ) | 
						
							| 32 |  | eluzfz1 |  |-  ( N e. ( ZZ>= ` 1 ) -> 1 e. ( 1 ... N ) ) | 
						
							| 33 | 31 32 | sylbi |  |-  ( N e. NN -> 1 e. ( 1 ... N ) ) | 
						
							| 34 |  | df-3 |  |-  3 = ( 2 + 1 ) | 
						
							| 35 |  | 1e0p1 |  |-  1 = ( 0 + 1 ) | 
						
							| 36 | 34 35 | eqeq12i |  |-  ( 3 = 1 <-> ( 2 + 1 ) = ( 0 + 1 ) ) | 
						
							| 37 |  | 2cn |  |-  2 e. CC | 
						
							| 38 |  | 0cn |  |-  0 e. CC | 
						
							| 39 | 37 38 10 | addcan2i |  |-  ( ( 2 + 1 ) = ( 0 + 1 ) <-> 2 = 0 ) | 
						
							| 40 | 36 39 | bitri |  |-  ( 3 = 1 <-> 2 = 0 ) | 
						
							| 41 | 40 | necon3bii |  |-  ( 3 =/= 1 <-> 2 =/= 0 ) | 
						
							| 42 | 3 41 | mpbir |  |-  3 =/= 1 | 
						
							| 43 | 42 | necomi |  |-  1 =/= 3 | 
						
							| 44 |  | eldifsn |  |-  ( 1 e. ( ( 1 ... N ) \ { 3 } ) <-> ( 1 e. ( 1 ... N ) /\ 1 =/= 3 ) ) | 
						
							| 45 | 33 43 44 | sylanblrc |  |-  ( N e. NN -> 1 e. ( ( 1 ... N ) \ { 3 } ) ) | 
						
							| 46 | 45 | adantr |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> 1 e. ( ( 1 ... N ) \ { 3 } ) ) | 
						
							| 47 |  | ne0i |  |-  ( 1 e. ( ( 1 ... N ) \ { 3 } ) -> ( ( 1 ... N ) \ { 3 } ) =/= (/) ) | 
						
							| 48 |  | rnxp |  |-  ( ( ( 1 ... N ) \ { 3 } ) =/= (/) -> ran ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) = { 0 } ) | 
						
							| 49 | 46 47 48 | 3syl |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ran ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) = { 0 } ) | 
						
							| 50 | 30 49 | uneq12d |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ( ran { <. 3 , -u 1 >. } u. ran ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = ( { -u 1 } u. { 0 } ) ) | 
						
							| 51 |  | rnun |  |-  ran ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = ( ran { <. 3 , -u 1 >. } u. ran ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) | 
						
							| 52 |  | df-pr |  |-  { -u 1 , 0 } = ( { -u 1 } u. { 0 } ) | 
						
							| 53 | 50 51 52 | 3eqtr4g |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ran ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = { -u 1 , 0 } ) | 
						
							| 54 |  | ovex |  |-  ( I + 1 ) e. _V | 
						
							| 55 | 54 | rnsnop |  |-  ran { <. ( I + 1 ) , 1 >. } = { 1 } | 
						
							| 56 | 55 | a1i |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ran { <. ( I + 1 ) , 1 >. } = { 1 } ) | 
						
							| 57 |  | nnz |  |-  ( N e. NN -> N e. ZZ ) | 
						
							| 58 |  | fzssp1 |  |-  ( 1 ... ( N - 1 ) ) C_ ( 1 ... ( ( N - 1 ) + 1 ) ) | 
						
							| 59 |  | zcn |  |-  ( N e. ZZ -> N e. CC ) | 
						
							| 60 |  | npcan1 |  |-  ( N e. CC -> ( ( N - 1 ) + 1 ) = N ) | 
						
							| 61 | 60 | oveq2d |  |-  ( N e. CC -> ( 1 ... ( ( N - 1 ) + 1 ) ) = ( 1 ... N ) ) | 
						
							| 62 | 59 61 | syl |  |-  ( N e. ZZ -> ( 1 ... ( ( N - 1 ) + 1 ) ) = ( 1 ... N ) ) | 
						
							| 63 | 58 62 | sseqtrid |  |-  ( N e. ZZ -> ( 1 ... ( N - 1 ) ) C_ ( 1 ... N ) ) | 
						
							| 64 | 57 63 | syl |  |-  ( N e. NN -> ( 1 ... ( N - 1 ) ) C_ ( 1 ... N ) ) | 
						
							| 65 | 64 | sselda |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> I e. ( 1 ... N ) ) | 
						
							| 66 |  | elfzelz |  |-  ( I e. ( 1 ... ( N - 1 ) ) -> I e. ZZ ) | 
						
							| 67 | 66 | zred |  |-  ( I e. ( 1 ... ( N - 1 ) ) -> I e. RR ) | 
						
							| 68 |  | id |  |-  ( I e. RR -> I e. RR ) | 
						
							| 69 |  | ltp1 |  |-  ( I e. RR -> I < ( I + 1 ) ) | 
						
							| 70 | 68 69 | ltned |  |-  ( I e. RR -> I =/= ( I + 1 ) ) | 
						
							| 71 | 67 70 | syl |  |-  ( I e. ( 1 ... ( N - 1 ) ) -> I =/= ( I + 1 ) ) | 
						
							| 72 | 71 | adantl |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> I =/= ( I + 1 ) ) | 
						
							| 73 |  | eldifsn |  |-  ( I e. ( ( 1 ... N ) \ { ( I + 1 ) } ) <-> ( I e. ( 1 ... N ) /\ I =/= ( I + 1 ) ) ) | 
						
							| 74 | 65 72 73 | sylanbrc |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> I e. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) | 
						
							| 75 |  | ne0i |  |-  ( I e. ( ( 1 ... N ) \ { ( I + 1 ) } ) -> ( ( 1 ... N ) \ { ( I + 1 ) } ) =/= (/) ) | 
						
							| 76 |  | rnxp |  |-  ( ( ( 1 ... N ) \ { ( I + 1 ) } ) =/= (/) -> ran ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) = { 0 } ) | 
						
							| 77 | 74 75 76 | 3syl |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ran ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) = { 0 } ) | 
						
							| 78 | 56 77 | uneq12d |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ( ran { <. ( I + 1 ) , 1 >. } u. ran ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) = ( { 1 } u. { 0 } ) ) | 
						
							| 79 |  | rnun |  |-  ran ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) = ( ran { <. ( I + 1 ) , 1 >. } u. ran ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) | 
						
							| 80 |  | df-pr |  |-  { 1 , 0 } = ( { 1 } u. { 0 } ) | 
						
							| 81 | 78 79 80 | 3eqtr4g |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ran ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) = { 1 , 0 } ) | 
						
							| 82 | 53 81 | eqeq12d |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ( ran ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = ran ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) <-> { -u 1 , 0 } = { 1 , 0 } ) ) | 
						
							| 83 | 27 82 | mtbiri |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> -. ran ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = ran ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) ) | 
						
							| 84 |  | rneq |  |-  ( ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) -> ran ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = ran ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) ) | 
						
							| 85 | 83 84 | nsyl |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> -. ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) ) | 
						
							| 86 | 1 2 | eqeq12i |  |-  ( P = Q <-> ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) ) | 
						
							| 87 | 86 | necon3abii |  |-  ( P =/= Q <-> -. ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) = ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) ) | 
						
							| 88 | 85 87 | sylibr |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> P =/= Q ) |