| Step | Hyp | Ref | Expression | 
						
							| 1 |  | axlowdimlem7.1 |  |-  P = ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) | 
						
							| 2 |  | eqid |  |-  { <. 3 , -u 1 >. } = { <. 3 , -u 1 >. } | 
						
							| 3 |  | 3ex |  |-  3 e. _V | 
						
							| 4 |  | negex |  |-  -u 1 e. _V | 
						
							| 5 | 3 4 | fsn |  |-  ( { <. 3 , -u 1 >. } : { 3 } --> { -u 1 } <-> { <. 3 , -u 1 >. } = { <. 3 , -u 1 >. } ) | 
						
							| 6 | 2 5 | mpbir |  |-  { <. 3 , -u 1 >. } : { 3 } --> { -u 1 } | 
						
							| 7 |  | neg1rr |  |-  -u 1 e. RR | 
						
							| 8 |  | snssi |  |-  ( -u 1 e. RR -> { -u 1 } C_ RR ) | 
						
							| 9 | 7 8 | ax-mp |  |-  { -u 1 } C_ RR | 
						
							| 10 |  | fss |  |-  ( ( { <. 3 , -u 1 >. } : { 3 } --> { -u 1 } /\ { -u 1 } C_ RR ) -> { <. 3 , -u 1 >. } : { 3 } --> RR ) | 
						
							| 11 | 6 9 10 | mp2an |  |-  { <. 3 , -u 1 >. } : { 3 } --> RR | 
						
							| 12 |  | 0re |  |-  0 e. RR | 
						
							| 13 | 12 | fconst6 |  |-  ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) : ( ( 1 ... N ) \ { 3 } ) --> RR | 
						
							| 14 | 11 13 | pm3.2i |  |-  ( { <. 3 , -u 1 >. } : { 3 } --> RR /\ ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) : ( ( 1 ... N ) \ { 3 } ) --> RR ) | 
						
							| 15 |  | disjdif |  |-  ( { 3 } i^i ( ( 1 ... N ) \ { 3 } ) ) = (/) | 
						
							| 16 |  | fun2 |  |-  ( ( ( { <. 3 , -u 1 >. } : { 3 } --> RR /\ ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) : ( ( 1 ... N ) \ { 3 } ) --> RR ) /\ ( { 3 } i^i ( ( 1 ... N ) \ { 3 } ) ) = (/) ) -> ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) : ( { 3 } u. ( ( 1 ... N ) \ { 3 } ) ) --> RR ) | 
						
							| 17 | 14 15 16 | mp2an |  |-  ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) : ( { 3 } u. ( ( 1 ... N ) \ { 3 } ) ) --> RR | 
						
							| 18 |  | eluzle |  |-  ( N e. ( ZZ>= ` 3 ) -> 3 <_ N ) | 
						
							| 19 |  | 1le3 |  |-  1 <_ 3 | 
						
							| 20 | 18 19 | jctil |  |-  ( N e. ( ZZ>= ` 3 ) -> ( 1 <_ 3 /\ 3 <_ N ) ) | 
						
							| 21 |  | 3z |  |-  3 e. ZZ | 
						
							| 22 |  | 1z |  |-  1 e. ZZ | 
						
							| 23 |  | eluzelz |  |-  ( N e. ( ZZ>= ` 3 ) -> N e. ZZ ) | 
						
							| 24 |  | elfz |  |-  ( ( 3 e. ZZ /\ 1 e. ZZ /\ N e. ZZ ) -> ( 3 e. ( 1 ... N ) <-> ( 1 <_ 3 /\ 3 <_ N ) ) ) | 
						
							| 25 | 21 22 23 24 | mp3an12i |  |-  ( N e. ( ZZ>= ` 3 ) -> ( 3 e. ( 1 ... N ) <-> ( 1 <_ 3 /\ 3 <_ N ) ) ) | 
						
							| 26 | 20 25 | mpbird |  |-  ( N e. ( ZZ>= ` 3 ) -> 3 e. ( 1 ... N ) ) | 
						
							| 27 | 26 | snssd |  |-  ( N e. ( ZZ>= ` 3 ) -> { 3 } C_ ( 1 ... N ) ) | 
						
							| 28 |  | undif |  |-  ( { 3 } C_ ( 1 ... N ) <-> ( { 3 } u. ( ( 1 ... N ) \ { 3 } ) ) = ( 1 ... N ) ) | 
						
							| 29 | 27 28 | sylib |  |-  ( N e. ( ZZ>= ` 3 ) -> ( { 3 } u. ( ( 1 ... N ) \ { 3 } ) ) = ( 1 ... N ) ) | 
						
							| 30 | 29 | feq2d |  |-  ( N e. ( ZZ>= ` 3 ) -> ( ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) : ( { 3 } u. ( ( 1 ... N ) \ { 3 } ) ) --> RR <-> ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) : ( 1 ... N ) --> RR ) ) | 
						
							| 31 | 17 30 | mpbii |  |-  ( N e. ( ZZ>= ` 3 ) -> ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) : ( 1 ... N ) --> RR ) | 
						
							| 32 |  | eluzge3nn |  |-  ( N e. ( ZZ>= ` 3 ) -> N e. NN ) | 
						
							| 33 |  | elee |  |-  ( N e. NN -> ( ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) e. ( EE ` N ) <-> ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) : ( 1 ... N ) --> RR ) ) | 
						
							| 34 | 32 33 | syl |  |-  ( N e. ( ZZ>= ` 3 ) -> ( ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) e. ( EE ` N ) <-> ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) : ( 1 ... N ) --> RR ) ) | 
						
							| 35 | 31 34 | mpbird |  |-  ( N e. ( ZZ>= ` 3 ) -> ( { <. 3 , -u 1 >. } u. ( ( ( 1 ... N ) \ { 3 } ) X. { 0 } ) ) e. ( EE ` N ) ) | 
						
							| 36 | 1 35 | eqeltrid |  |-  ( N e. ( ZZ>= ` 3 ) -> P e. ( EE ` N ) ) |