| Step | Hyp | Ref | Expression | 
						
							| 1 |  | axlowdimlem10.1 |  |-  Q = ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) | 
						
							| 2 |  | ovex |  |-  ( I + 1 ) e. _V | 
						
							| 3 |  | 1ex |  |-  1 e. _V | 
						
							| 4 | 2 3 | f1osn |  |-  { <. ( I + 1 ) , 1 >. } : { ( I + 1 ) } -1-1-onto-> { 1 } | 
						
							| 5 |  | f1of |  |-  ( { <. ( I + 1 ) , 1 >. } : { ( I + 1 ) } -1-1-onto-> { 1 } -> { <. ( I + 1 ) , 1 >. } : { ( I + 1 ) } --> { 1 } ) | 
						
							| 6 | 4 5 | ax-mp |  |-  { <. ( I + 1 ) , 1 >. } : { ( I + 1 ) } --> { 1 } | 
						
							| 7 |  | c0ex |  |-  0 e. _V | 
						
							| 8 | 7 | fconst |  |-  ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) : ( ( 1 ... N ) \ { ( I + 1 ) } ) --> { 0 } | 
						
							| 9 | 6 8 | pm3.2i |  |-  ( { <. ( I + 1 ) , 1 >. } : { ( I + 1 ) } --> { 1 } /\ ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) : ( ( 1 ... N ) \ { ( I + 1 ) } ) --> { 0 } ) | 
						
							| 10 |  | disjdif |  |-  ( { ( I + 1 ) } i^i ( ( 1 ... N ) \ { ( I + 1 ) } ) ) = (/) | 
						
							| 11 |  | fun |  |-  ( ( ( { <. ( I + 1 ) , 1 >. } : { ( I + 1 ) } --> { 1 } /\ ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) : ( ( 1 ... N ) \ { ( I + 1 ) } ) --> { 0 } ) /\ ( { ( I + 1 ) } i^i ( ( 1 ... N ) \ { ( I + 1 ) } ) ) = (/) ) -> ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) : ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) --> ( { 1 } u. { 0 } ) ) | 
						
							| 12 | 9 10 11 | mp2an |  |-  ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) : ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) --> ( { 1 } u. { 0 } ) | 
						
							| 13 | 1 | feq1i |  |-  ( Q : ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) --> ( { 1 } u. { 0 } ) <-> ( { <. ( I + 1 ) , 1 >. } u. ( ( ( 1 ... N ) \ { ( I + 1 ) } ) X. { 0 } ) ) : ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) --> ( { 1 } u. { 0 } ) ) | 
						
							| 14 | 12 13 | mpbir |  |-  Q : ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) --> ( { 1 } u. { 0 } ) | 
						
							| 15 |  | 1re |  |-  1 e. RR | 
						
							| 16 |  | snssi |  |-  ( 1 e. RR -> { 1 } C_ RR ) | 
						
							| 17 | 15 16 | ax-mp |  |-  { 1 } C_ RR | 
						
							| 18 |  | 0re |  |-  0 e. RR | 
						
							| 19 |  | snssi |  |-  ( 0 e. RR -> { 0 } C_ RR ) | 
						
							| 20 | 18 19 | ax-mp |  |-  { 0 } C_ RR | 
						
							| 21 | 17 20 | unssi |  |-  ( { 1 } u. { 0 } ) C_ RR | 
						
							| 22 |  | fss |  |-  ( ( Q : ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) --> ( { 1 } u. { 0 } ) /\ ( { 1 } u. { 0 } ) C_ RR ) -> Q : ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) --> RR ) | 
						
							| 23 | 14 21 22 | mp2an |  |-  Q : ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) --> RR | 
						
							| 24 |  | fznatpl1 |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ( I + 1 ) e. ( 1 ... N ) ) | 
						
							| 25 | 24 | snssd |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> { ( I + 1 ) } C_ ( 1 ... N ) ) | 
						
							| 26 |  | undif |  |-  ( { ( I + 1 ) } C_ ( 1 ... N ) <-> ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) = ( 1 ... N ) ) | 
						
							| 27 | 25 26 | sylib |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) = ( 1 ... N ) ) | 
						
							| 28 | 27 | feq2d |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ( Q : ( { ( I + 1 ) } u. ( ( 1 ... N ) \ { ( I + 1 ) } ) ) --> RR <-> Q : ( 1 ... N ) --> RR ) ) | 
						
							| 29 | 23 28 | mpbii |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> Q : ( 1 ... N ) --> RR ) | 
						
							| 30 |  | elee |  |-  ( N e. NN -> ( Q e. ( EE ` N ) <-> Q : ( 1 ... N ) --> RR ) ) | 
						
							| 31 | 30 | adantr |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> ( Q e. ( EE ` N ) <-> Q : ( 1 ... N ) --> RR ) ) | 
						
							| 32 | 29 31 | mpbird |  |-  ( ( N e. NN /\ I e. ( 1 ... ( N - 1 ) ) ) -> Q e. ( EE ` N ) ) |