| Step | Hyp | Ref | Expression | 
						
							| 1 |  | axlowdimlem14.1 |  |-  Q = ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) | 
						
							| 2 |  | axlowdimlem14.2 |  |-  R = ( { <. ( J + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( J + 1 ) } ) X. { 0 } ) ) | 
						
							| 3 | 1 | axlowdimlem10 |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> Q e. ( EE ` N ) ) | 
						
							| 4 |  | elee |  |-  ( N e. NN -> ( Q e. ( EE ` N ) <-> Q : ( 1 ... N ) --> RR ) ) | 
						
							| 5 | 4 | adantr |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ( Q e. ( EE ` N ) <-> Q : ( 1 ... N ) --> RR ) ) | 
						
							| 6 | 3 5 | mpbid |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> Q : ( 1 ... N ) --> RR ) | 
						
							| 7 | 6 | ffnd |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> Q Fn ( 1 ... N ) ) | 
						
							| 8 | 2 | axlowdimlem10 |  |-  ( ( N e. NN /\ J e. ( 1 ... ( N - 1 ) ) ) -> R e. ( EE ` N ) ) | 
						
							| 9 |  | elee |  |-  ( N e. NN -> ( R e. ( EE ` N ) <-> R : ( 1 ... N ) --> RR ) ) | 
						
							| 10 | 9 | adantr |  |-  ( ( N e. NN /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( R e. ( EE ` N ) <-> R : ( 1 ... N ) --> RR ) ) | 
						
							| 11 | 8 10 | mpbid |  |-  ( ( N e. NN /\ J e. ( 1 ... ( N - 1 ) ) ) -> R : ( 1 ... N ) --> RR ) | 
						
							| 12 | 11 | ffnd |  |-  ( ( N e. NN /\ J e. ( 1 ... ( N - 1 ) ) ) -> R Fn ( 1 ... N ) ) | 
						
							| 13 |  | eqfnfv |  |-  ( ( Q Fn ( 1 ... N ) /\ R Fn ( 1 ... N ) ) -> ( Q = R <-> A. i e. ( 1 ... N ) ( Q ` i ) = ( R ` i ) ) ) | 
						
							| 14 | 7 12 13 | syl2an |  |-  ( ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) /\ ( N e. NN /\ J e. ( 1 ... ( N - 1 ) ) ) ) -> ( Q = R <-> A. i e. ( 1 ... N ) ( Q ` i ) = ( R ` i ) ) ) | 
						
							| 15 | 14 | 3impdi |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( Q = R <-> A. i e. ( 1 ... N ) ( Q ` i ) = ( R ` i ) ) ) | 
						
							| 16 |  | fznatpl1 |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ( I + 1 ) e. ( 1 ... N ) ) | 
						
							| 17 | 16 | 3adant3 |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( I + 1 ) e. ( 1 ... N ) ) | 
						
							| 18 |  | ax-1ne0 |  |-  1 =/= 0 | 
						
							| 19 | 18 | a1i |  |-  ( ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) /\ I =/= J ) -> 1 =/= 0 ) | 
						
							| 20 | 1 | axlowdimlem11 |  |-  ( Q ` ( I + 1 ) ) = 1 | 
						
							| 21 | 20 | a1i |  |-  ( ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) /\ I =/= J ) -> ( Q ` ( I + 1 ) ) = 1 ) | 
						
							| 22 |  | elfzelz |  |-  ( I e. ( 1 ... ( N - 1 ) ) -> I e. ZZ ) | 
						
							| 23 | 22 | zcnd |  |-  ( I e. ( 1 ... ( N - 1 ) ) -> I e. CC ) | 
						
							| 24 |  | elfzelz |  |-  ( J e. ( 1 ... ( N - 1 ) ) -> J e. ZZ ) | 
						
							| 25 | 24 | zcnd |  |-  ( J e. ( 1 ... ( N - 1 ) ) -> J e. CC ) | 
						
							| 26 |  | ax-1cn |  |-  1 e. CC | 
						
							| 27 |  | addcan2 |  |-  ( ( I e. CC /\ J e. CC /\ 1 e. CC ) -> ( ( I + 1 ) = ( J + 1 ) <-> I = J ) ) | 
						
							| 28 | 26 27 | mp3an3 |  |-  ( ( I e. CC /\ J e. CC ) -> ( ( I + 1 ) = ( J + 1 ) <-> I = J ) ) | 
						
							| 29 | 23 25 28 | syl2an |  |-  ( ( I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( ( I + 1 ) = ( J + 1 ) <-> I = J ) ) | 
						
							| 30 | 29 | 3adant1 |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( ( I + 1 ) = ( J + 1 ) <-> I = J ) ) | 
						
							| 31 | 30 | necon3bid |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( ( I + 1 ) =/= ( J + 1 ) <-> I =/= J ) ) | 
						
							| 32 | 31 | biimpar |  |-  ( ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) /\ I =/= J ) -> ( I + 1 ) =/= ( J + 1 ) ) | 
						
							| 33 | 2 | axlowdimlem12 |  |-  ( ( ( I + 1 ) e. ( 1 ... N ) /\ ( I + 1 ) =/= ( J + 1 ) ) -> ( R ` ( I + 1 ) ) = 0 ) | 
						
							| 34 | 17 32 33 | syl2an2r |  |-  ( ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) /\ I =/= J ) -> ( R ` ( I + 1 ) ) = 0 ) | 
						
							| 35 | 19 21 34 | 3netr4d |  |-  ( ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) /\ I =/= J ) -> ( Q ` ( I + 1 ) ) =/= ( R ` ( I + 1 ) ) ) | 
						
							| 36 |  | df-ne |  |-  ( ( Q ` i ) =/= ( R ` i ) <-> -. ( Q ` i ) = ( R ` i ) ) | 
						
							| 37 |  | fveq2 |  |-  ( i = ( I + 1 ) -> ( Q ` i ) = ( Q ` ( I + 1 ) ) ) | 
						
							| 38 |  | fveq2 |  |-  ( i = ( I + 1 ) -> ( R ` i ) = ( R ` ( I + 1 ) ) ) | 
						
							| 39 | 37 38 | neeq12d |  |-  ( i = ( I + 1 ) -> ( ( Q ` i ) =/= ( R ` i ) <-> ( Q ` ( I + 1 ) ) =/= ( R ` ( I + 1 ) ) ) ) | 
						
							| 40 | 36 39 | bitr3id |  |-  ( i = ( I + 1 ) -> ( -. ( Q ` i ) = ( R ` i ) <-> ( Q ` ( I + 1 ) ) =/= ( R ` ( I + 1 ) ) ) ) | 
						
							| 41 | 40 | rspcev |  |-  ( ( ( I + 1 ) e. ( 1 ... N ) /\ ( Q ` ( I + 1 ) ) =/= ( R ` ( I + 1 ) ) ) -> E. i e. ( 1 ... N ) -. ( Q ` i ) = ( R ` i ) ) | 
						
							| 42 | 17 35 41 | syl2an2r |  |-  ( ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) /\ I =/= J ) -> E. i e. ( 1 ... N ) -. ( Q ` i ) = ( R ` i ) ) | 
						
							| 43 | 42 | ex |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( I =/= J -> E. i e. ( 1 ... N ) -. ( Q ` i ) = ( R ` i ) ) ) | 
						
							| 44 |  | df-ne |  |-  ( I =/= J <-> -. I = J ) | 
						
							| 45 |  | rexnal |  |-  ( E. i e. ( 1 ... N ) -. ( Q ` i ) = ( R ` i ) <-> -. A. i e. ( 1 ... N ) ( Q ` i ) = ( R ` i ) ) | 
						
							| 46 | 43 44 45 | 3imtr3g |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( -. I = J -> -. A. i e. ( 1 ... N ) ( Q ` i ) = ( R ` i ) ) ) | 
						
							| 47 | 46 | con4d |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( A. i e. ( 1 ... N ) ( Q ` i ) = ( R ` i ) -> I = J ) ) | 
						
							| 48 | 15 47 | sylbid |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) /\ J e. ( 1 ... ( N - 1 ) ) ) -> ( Q = R -> I = J ) ) |