| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fmtnonn |  |-  ( N e. NN0 -> ( FermatNo ` N ) e. NN ) | 
						
							| 2 | 1 | nnzd |  |-  ( N e. NN0 -> ( FermatNo ` N ) e. ZZ ) | 
						
							| 3 |  | fmtnonn |  |-  ( M e. NN0 -> ( FermatNo ` M ) e. NN ) | 
						
							| 4 | 3 | nnzd |  |-  ( M e. NN0 -> ( FermatNo ` M ) e. ZZ ) | 
						
							| 5 | 2 4 | anim12ci |  |-  ( ( N e. NN0 /\ M e. NN0 ) -> ( ( FermatNo ` M ) e. ZZ /\ ( FermatNo ` N ) e. ZZ ) ) | 
						
							| 6 | 5 | 3adant3 |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( FermatNo ` M ) e. ZZ /\ ( FermatNo ` N ) e. ZZ ) ) | 
						
							| 7 |  | gcddvds |  |-  ( ( ( FermatNo ` M ) e. ZZ /\ ( FermatNo ` N ) e. ZZ ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` M ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) ) ) | 
						
							| 8 | 6 7 | syl |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` M ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) ) ) | 
						
							| 9 |  | goldbachthlem1 |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( FermatNo ` M ) || ( ( FermatNo ` N ) - 2 ) ) | 
						
							| 10 |  | gcdcl |  |-  ( ( ( FermatNo ` M ) e. ZZ /\ ( FermatNo ` N ) e. ZZ ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) e. NN0 ) | 
						
							| 11 | 6 10 | syl |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) e. NN0 ) | 
						
							| 12 | 11 | nn0zd |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) e. ZZ ) | 
						
							| 13 | 4 | 3ad2ant2 |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( FermatNo ` M ) e. ZZ ) | 
						
							| 14 |  | 2z |  |-  2 e. ZZ | 
						
							| 15 | 14 | a1i |  |-  ( N e. NN0 -> 2 e. ZZ ) | 
						
							| 16 | 2 15 | zsubcld |  |-  ( N e. NN0 -> ( ( FermatNo ` N ) - 2 ) e. ZZ ) | 
						
							| 17 | 16 | 3ad2ant1 |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( FermatNo ` N ) - 2 ) e. ZZ ) | 
						
							| 18 |  | dvdstr |  |-  ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) e. ZZ /\ ( FermatNo ` M ) e. ZZ /\ ( ( FermatNo ` N ) - 2 ) e. ZZ ) -> ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` M ) /\ ( FermatNo ` M ) || ( ( FermatNo ` N ) - 2 ) ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - 2 ) ) ) | 
						
							| 19 | 12 13 17 18 | syl3anc |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` M ) /\ ( FermatNo ` M ) || ( ( FermatNo ` N ) - 2 ) ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - 2 ) ) ) | 
						
							| 20 | 9 19 | mpan2d |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` M ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - 2 ) ) ) | 
						
							| 21 | 2 | 3ad2ant1 |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( FermatNo ` N ) e. ZZ ) | 
						
							| 22 |  | dvds2sub |  |-  ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) e. ZZ /\ ( FermatNo ` N ) e. ZZ /\ ( ( FermatNo ` N ) - 2 ) e. ZZ ) -> ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - 2 ) ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - ( ( FermatNo ` N ) - 2 ) ) ) ) | 
						
							| 23 | 12 21 17 22 | syl3anc |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - 2 ) ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - ( ( FermatNo ` N ) - 2 ) ) ) ) | 
						
							| 24 | 23 | ancomsd |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - 2 ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - ( ( FermatNo ` N ) - 2 ) ) ) ) | 
						
							| 25 | 1 | nncnd |  |-  ( N e. NN0 -> ( FermatNo ` N ) e. CC ) | 
						
							| 26 | 25 | 3ad2ant1 |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( FermatNo ` N ) e. CC ) | 
						
							| 27 |  | 2cnd |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> 2 e. CC ) | 
						
							| 28 | 26 27 | nncand |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( FermatNo ` N ) - ( ( FermatNo ` N ) - 2 ) ) = 2 ) | 
						
							| 29 | 28 | breq2d |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - ( ( FermatNo ` N ) - 2 ) ) <-> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || 2 ) ) | 
						
							| 30 |  | 2prm |  |-  2 e. Prime | 
						
							| 31 | 1 3 | anim12ci |  |-  ( ( N e. NN0 /\ M e. NN0 ) -> ( ( FermatNo ` M ) e. NN /\ ( FermatNo ` N ) e. NN ) ) | 
						
							| 32 | 31 | 3adant3 |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( FermatNo ` M ) e. NN /\ ( FermatNo ` N ) e. NN ) ) | 
						
							| 33 |  | gcdnncl |  |-  ( ( ( FermatNo ` M ) e. NN /\ ( FermatNo ` N ) e. NN ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) e. NN ) | 
						
							| 34 | 32 33 | syl |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) e. NN ) | 
						
							| 35 |  | dvdsprime |  |-  ( ( 2 e. Prime /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) e. NN ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || 2 <-> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 \/ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 1 ) ) ) | 
						
							| 36 | 30 34 35 | sylancr |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || 2 <-> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 \/ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 1 ) ) ) | 
						
							| 37 | 5 7 | syl |  |-  ( ( N e. NN0 /\ M e. NN0 ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` M ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) ) ) | 
						
							| 38 |  | breq1 |  |-  ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) <-> 2 || ( FermatNo ` N ) ) ) | 
						
							| 39 | 38 | adantl |  |-  ( ( ( N e. NN0 /\ M e. NN0 ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) <-> 2 || ( FermatNo ` N ) ) ) | 
						
							| 40 |  | fmtnoodd |  |-  ( N e. NN0 -> -. 2 || ( FermatNo ` N ) ) | 
						
							| 41 | 40 | pm2.21d |  |-  ( N e. NN0 -> ( 2 || ( FermatNo ` N ) -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 42 | 41 | ad2antrr |  |-  ( ( ( N e. NN0 /\ M e. NN0 ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 ) -> ( 2 || ( FermatNo ` N ) -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 43 | 39 42 | sylbid |  |-  ( ( ( N e. NN0 /\ M e. NN0 ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 44 | 43 | ex |  |-  ( ( N e. NN0 /\ M e. NN0 ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) ) | 
						
							| 45 | 44 | com23 |  |-  ( ( N e. NN0 /\ M e. NN0 ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) ) | 
						
							| 46 | 45 | adantld |  |-  ( ( N e. NN0 /\ M e. NN0 ) -> ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` M ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) ) | 
						
							| 47 | 37 46 | mpd |  |-  ( ( N e. NN0 /\ M e. NN0 ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 48 | 47 | 3adant3 |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 49 |  | gcdcom |  |-  ( ( ( FermatNo ` M ) e. ZZ /\ ( FermatNo ` N ) e. ZZ ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) ) | 
						
							| 50 | 6 49 | syl |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) ) | 
						
							| 51 | 50 | eqeq1d |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 1 <-> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 52 | 51 | biimpd |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 1 -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 53 | 48 52 | jaod |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 2 \/ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) = 1 ) -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 54 | 36 53 | sylbid |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || 2 -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 55 | 29 54 | sylbid |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - ( ( FermatNo ` N ) - 2 ) ) -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 56 | 24 55 | syld |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( ( FermatNo ` N ) - 2 ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) ) -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 57 | 20 56 | syland |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` M ) /\ ( ( FermatNo ` M ) gcd ( FermatNo ` N ) ) || ( FermatNo ` N ) ) -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) ) | 
						
							| 58 | 8 57 | mpd |  |-  ( ( N e. NN0 /\ M e. NN0 /\ M < N ) -> ( ( FermatNo ` N ) gcd ( FermatNo ` M ) ) = 1 ) |