| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 3odd |  |-  3 e. Odd | 
						
							| 2 | 1 | a1i |  |-  ( N e. ( ZZ>= ` ; 1 2 ) -> 3 e. Odd ) | 
						
							| 3 | 2 | anim1i |  |-  ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) -> ( 3 e. Odd /\ N e. Even ) ) | 
						
							| 4 | 3 | ancomd |  |-  ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) -> ( N e. Even /\ 3 e. Odd ) ) | 
						
							| 5 |  | emoo |  |-  ( ( N e. Even /\ 3 e. Odd ) -> ( N - 3 ) e. Odd ) | 
						
							| 6 | 4 5 | syl |  |-  ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) -> ( N - 3 ) e. Odd ) | 
						
							| 7 |  | breq2 |  |-  ( m = ( N - 3 ) -> ( 7 < m <-> 7 < ( N - 3 ) ) ) | 
						
							| 8 |  | eleq1 |  |-  ( m = ( N - 3 ) -> ( m e. GoldbachOdd <-> ( N - 3 ) e. GoldbachOdd ) ) | 
						
							| 9 | 7 8 | imbi12d |  |-  ( m = ( N - 3 ) -> ( ( 7 < m -> m e. GoldbachOdd ) <-> ( 7 < ( N - 3 ) -> ( N - 3 ) e. GoldbachOdd ) ) ) | 
						
							| 10 | 9 | adantl |  |-  ( ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) /\ m = ( N - 3 ) ) -> ( ( 7 < m -> m e. GoldbachOdd ) <-> ( 7 < ( N - 3 ) -> ( N - 3 ) e. GoldbachOdd ) ) ) | 
						
							| 11 | 6 10 | rspcdv |  |-  ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) -> ( A. m e. Odd ( 7 < m -> m e. GoldbachOdd ) -> ( 7 < ( N - 3 ) -> ( N - 3 ) e. GoldbachOdd ) ) ) | 
						
							| 12 |  | eluz2 |  |-  ( N e. ( ZZ>= ` ; 1 2 ) <-> ( ; 1 2 e. ZZ /\ N e. ZZ /\ ; 1 2 <_ N ) ) | 
						
							| 13 |  | 7p3e10 |  |-  ( 7 + 3 ) = ; 1 0 | 
						
							| 14 |  | 1nn0 |  |-  1 e. NN0 | 
						
							| 15 |  | 0nn0 |  |-  0 e. NN0 | 
						
							| 16 |  | 2nn |  |-  2 e. NN | 
						
							| 17 |  | 2pos |  |-  0 < 2 | 
						
							| 18 | 14 15 16 17 | declt |  |-  ; 1 0 < ; 1 2 | 
						
							| 19 | 13 18 | eqbrtri |  |-  ( 7 + 3 ) < ; 1 2 | 
						
							| 20 |  | 7re |  |-  7 e. RR | 
						
							| 21 |  | 3re |  |-  3 e. RR | 
						
							| 22 | 20 21 | readdcli |  |-  ( 7 + 3 ) e. RR | 
						
							| 23 |  | 2nn0 |  |-  2 e. NN0 | 
						
							| 24 | 14 23 | deccl |  |-  ; 1 2 e. NN0 | 
						
							| 25 | 24 | nn0rei |  |-  ; 1 2 e. RR | 
						
							| 26 |  | zre |  |-  ( N e. ZZ -> N e. RR ) | 
						
							| 27 |  | ltletr |  |-  ( ( ( 7 + 3 ) e. RR /\ ; 1 2 e. RR /\ N e. RR ) -> ( ( ( 7 + 3 ) < ; 1 2 /\ ; 1 2 <_ N ) -> ( 7 + 3 ) < N ) ) | 
						
							| 28 | 22 25 26 27 | mp3an12i |  |-  ( N e. ZZ -> ( ( ( 7 + 3 ) < ; 1 2 /\ ; 1 2 <_ N ) -> ( 7 + 3 ) < N ) ) | 
						
							| 29 | 19 28 | mpani |  |-  ( N e. ZZ -> ( ; 1 2 <_ N -> ( 7 + 3 ) < N ) ) | 
						
							| 30 | 29 | imp |  |-  ( ( N e. ZZ /\ ; 1 2 <_ N ) -> ( 7 + 3 ) < N ) | 
						
							| 31 | 30 | 3adant1 |  |-  ( ( ; 1 2 e. ZZ /\ N e. ZZ /\ ; 1 2 <_ N ) -> ( 7 + 3 ) < N ) | 
						
							| 32 | 20 | a1i |  |-  ( ( ; 1 2 e. ZZ /\ N e. ZZ /\ ; 1 2 <_ N ) -> 7 e. RR ) | 
						
							| 33 | 21 | a1i |  |-  ( ( ; 1 2 e. ZZ /\ N e. ZZ /\ ; 1 2 <_ N ) -> 3 e. RR ) | 
						
							| 34 | 26 | 3ad2ant2 |  |-  ( ( ; 1 2 e. ZZ /\ N e. ZZ /\ ; 1 2 <_ N ) -> N e. RR ) | 
						
							| 35 | 32 33 34 | ltaddsubd |  |-  ( ( ; 1 2 e. ZZ /\ N e. ZZ /\ ; 1 2 <_ N ) -> ( ( 7 + 3 ) < N <-> 7 < ( N - 3 ) ) ) | 
						
							| 36 | 31 35 | mpbid |  |-  ( ( ; 1 2 e. ZZ /\ N e. ZZ /\ ; 1 2 <_ N ) -> 7 < ( N - 3 ) ) | 
						
							| 37 | 12 36 | sylbi |  |-  ( N e. ( ZZ>= ` ; 1 2 ) -> 7 < ( N - 3 ) ) | 
						
							| 38 | 37 | adantr |  |-  ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) -> 7 < ( N - 3 ) ) | 
						
							| 39 |  | simpr |  |-  ( ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) /\ ( N - 3 ) e. GoldbachOdd ) -> ( N - 3 ) e. GoldbachOdd ) | 
						
							| 40 |  | oveq1 |  |-  ( o = ( N - 3 ) -> ( o + 3 ) = ( ( N - 3 ) + 3 ) ) | 
						
							| 41 | 40 | eqeq2d |  |-  ( o = ( N - 3 ) -> ( N = ( o + 3 ) <-> N = ( ( N - 3 ) + 3 ) ) ) | 
						
							| 42 | 41 | adantl |  |-  ( ( ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) /\ ( N - 3 ) e. GoldbachOdd ) /\ o = ( N - 3 ) ) -> ( N = ( o + 3 ) <-> N = ( ( N - 3 ) + 3 ) ) ) | 
						
							| 43 |  | eluzelcn |  |-  ( N e. ( ZZ>= ` ; 1 2 ) -> N e. CC ) | 
						
							| 44 |  | 3cn |  |-  3 e. CC | 
						
							| 45 | 43 44 | jctir |  |-  ( N e. ( ZZ>= ` ; 1 2 ) -> ( N e. CC /\ 3 e. CC ) ) | 
						
							| 46 | 45 | adantr |  |-  ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) -> ( N e. CC /\ 3 e. CC ) ) | 
						
							| 47 | 46 | adantr |  |-  ( ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) /\ ( N - 3 ) e. GoldbachOdd ) -> ( N e. CC /\ 3 e. CC ) ) | 
						
							| 48 |  | npcan |  |-  ( ( N e. CC /\ 3 e. CC ) -> ( ( N - 3 ) + 3 ) = N ) | 
						
							| 49 | 48 | eqcomd |  |-  ( ( N e. CC /\ 3 e. CC ) -> N = ( ( N - 3 ) + 3 ) ) | 
						
							| 50 | 47 49 | syl |  |-  ( ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) /\ ( N - 3 ) e. GoldbachOdd ) -> N = ( ( N - 3 ) + 3 ) ) | 
						
							| 51 | 39 42 50 | rspcedvd |  |-  ( ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) /\ ( N - 3 ) e. GoldbachOdd ) -> E. o e. GoldbachOdd N = ( o + 3 ) ) | 
						
							| 52 | 51 | ex |  |-  ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) -> ( ( N - 3 ) e. GoldbachOdd -> E. o e. GoldbachOdd N = ( o + 3 ) ) ) | 
						
							| 53 | 38 52 | embantd |  |-  ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) -> ( ( 7 < ( N - 3 ) -> ( N - 3 ) e. GoldbachOdd ) -> E. o e. GoldbachOdd N = ( o + 3 ) ) ) | 
						
							| 54 | 11 53 | syldc |  |-  ( A. m e. Odd ( 7 < m -> m e. GoldbachOdd ) -> ( ( N e. ( ZZ>= ` ; 1 2 ) /\ N e. Even ) -> E. o e. GoldbachOdd N = ( o + 3 ) ) ) |