Step |
Hyp |
Ref |
Expression |
1 |
|
peano2cnm |
|- ( C e. CC -> ( C - 1 ) e. CC ) |
2 |
|
id |
|- ( C e. CC -> C e. CC ) |
3 |
|
4cn |
|- 4 e. CC |
4 |
3
|
a1i |
|- ( C e. CC -> 4 e. CC ) |
5 |
2 4
|
subcld |
|- ( C e. CC -> ( C - 4 ) e. CC ) |
6 |
|
1cnd |
|- ( C e. CC -> 1 e. CC ) |
7 |
|
1re |
|- 1 e. RR |
8 |
|
1lt4 |
|- 1 < 4 |
9 |
7 8
|
ltneii |
|- 1 =/= 4 |
10 |
9
|
a1i |
|- ( C e. CC -> 1 =/= 4 ) |
11 |
2 6 4 10
|
subneintrd |
|- ( C e. CC -> ( C - 1 ) =/= ( C - 4 ) ) |
12 |
|
oveq1 |
|- ( b = 1 -> ( b ^ 2 ) = ( 1 ^ 2 ) ) |
13 |
12
|
oveq2d |
|- ( b = 1 -> ( ( C - 1 ) + ( b ^ 2 ) ) = ( ( C - 1 ) + ( 1 ^ 2 ) ) ) |
14 |
13
|
eqeq1d |
|- ( b = 1 -> ( ( ( C - 1 ) + ( b ^ 2 ) ) = C <-> ( ( C - 1 ) + ( 1 ^ 2 ) ) = C ) ) |
15 |
14
|
adantl |
|- ( ( C e. CC /\ b = 1 ) -> ( ( ( C - 1 ) + ( b ^ 2 ) ) = C <-> ( ( C - 1 ) + ( 1 ^ 2 ) ) = C ) ) |
16 |
|
sq1 |
|- ( 1 ^ 2 ) = 1 |
17 |
16
|
oveq2i |
|- ( ( C - 1 ) + ( 1 ^ 2 ) ) = ( ( C - 1 ) + 1 ) |
18 |
|
npcan1 |
|- ( C e. CC -> ( ( C - 1 ) + 1 ) = C ) |
19 |
17 18
|
syl5eq |
|- ( C e. CC -> ( ( C - 1 ) + ( 1 ^ 2 ) ) = C ) |
20 |
6 15 19
|
rspcedvd |
|- ( C e. CC -> E. b e. CC ( ( C - 1 ) + ( b ^ 2 ) ) = C ) |
21 |
|
2cnd |
|- ( C e. CC -> 2 e. CC ) |
22 |
|
oveq1 |
|- ( b = 2 -> ( b ^ 2 ) = ( 2 ^ 2 ) ) |
23 |
22
|
oveq2d |
|- ( b = 2 -> ( ( C - 4 ) + ( b ^ 2 ) ) = ( ( C - 4 ) + ( 2 ^ 2 ) ) ) |
24 |
23
|
eqeq1d |
|- ( b = 2 -> ( ( ( C - 4 ) + ( b ^ 2 ) ) = C <-> ( ( C - 4 ) + ( 2 ^ 2 ) ) = C ) ) |
25 |
24
|
adantl |
|- ( ( C e. CC /\ b = 2 ) -> ( ( ( C - 4 ) + ( b ^ 2 ) ) = C <-> ( ( C - 4 ) + ( 2 ^ 2 ) ) = C ) ) |
26 |
|
2cn |
|- 2 e. CC |
27 |
26
|
sqcli |
|- ( 2 ^ 2 ) e. CC |
28 |
27
|
a1i |
|- ( C e. CC -> ( 2 ^ 2 ) e. CC ) |
29 |
2 4 28
|
subadd23d |
|- ( C e. CC -> ( ( C - 4 ) + ( 2 ^ 2 ) ) = ( C + ( ( 2 ^ 2 ) - 4 ) ) ) |
30 |
|
sq2 |
|- ( 2 ^ 2 ) = 4 |
31 |
30
|
a1i |
|- ( C e. CC -> ( 2 ^ 2 ) = 4 ) |
32 |
28 31
|
subeq0bd |
|- ( C e. CC -> ( ( 2 ^ 2 ) - 4 ) = 0 ) |
33 |
27 3
|
subcli |
|- ( ( 2 ^ 2 ) - 4 ) e. CC |
34 |
|
addid0 |
|- ( ( C e. CC /\ ( ( 2 ^ 2 ) - 4 ) e. CC ) -> ( ( C + ( ( 2 ^ 2 ) - 4 ) ) = C <-> ( ( 2 ^ 2 ) - 4 ) = 0 ) ) |
35 |
33 34
|
mpan2 |
|- ( C e. CC -> ( ( C + ( ( 2 ^ 2 ) - 4 ) ) = C <-> ( ( 2 ^ 2 ) - 4 ) = 0 ) ) |
36 |
32 35
|
mpbird |
|- ( C e. CC -> ( C + ( ( 2 ^ 2 ) - 4 ) ) = C ) |
37 |
29 36
|
eqtrd |
|- ( C e. CC -> ( ( C - 4 ) + ( 2 ^ 2 ) ) = C ) |
38 |
21 25 37
|
rspcedvd |
|- ( C e. CC -> E. b e. CC ( ( C - 4 ) + ( b ^ 2 ) ) = C ) |
39 |
|
oveq1 |
|- ( a = ( C - 1 ) -> ( a + ( b ^ 2 ) ) = ( ( C - 1 ) + ( b ^ 2 ) ) ) |
40 |
39
|
eqeq1d |
|- ( a = ( C - 1 ) -> ( ( a + ( b ^ 2 ) ) = C <-> ( ( C - 1 ) + ( b ^ 2 ) ) = C ) ) |
41 |
40
|
rexbidv |
|- ( a = ( C - 1 ) -> ( E. b e. CC ( a + ( b ^ 2 ) ) = C <-> E. b e. CC ( ( C - 1 ) + ( b ^ 2 ) ) = C ) ) |
42 |
|
oveq1 |
|- ( a = ( C - 4 ) -> ( a + ( b ^ 2 ) ) = ( ( C - 4 ) + ( b ^ 2 ) ) ) |
43 |
42
|
eqeq1d |
|- ( a = ( C - 4 ) -> ( ( a + ( b ^ 2 ) ) = C <-> ( ( C - 4 ) + ( b ^ 2 ) ) = C ) ) |
44 |
43
|
rexbidv |
|- ( a = ( C - 4 ) -> ( E. b e. CC ( a + ( b ^ 2 ) ) = C <-> E. b e. CC ( ( C - 4 ) + ( b ^ 2 ) ) = C ) ) |
45 |
41 44
|
2nreu |
|- ( ( ( C - 1 ) e. CC /\ ( C - 4 ) e. CC /\ ( C - 1 ) =/= ( C - 4 ) ) -> ( ( E. b e. CC ( ( C - 1 ) + ( b ^ 2 ) ) = C /\ E. b e. CC ( ( C - 4 ) + ( b ^ 2 ) ) = C ) -> -. E! a e. CC E. b e. CC ( a + ( b ^ 2 ) ) = C ) ) |
46 |
45
|
imp |
|- ( ( ( ( C - 1 ) e. CC /\ ( C - 4 ) e. CC /\ ( C - 1 ) =/= ( C - 4 ) ) /\ ( E. b e. CC ( ( C - 1 ) + ( b ^ 2 ) ) = C /\ E. b e. CC ( ( C - 4 ) + ( b ^ 2 ) ) = C ) ) -> -. E! a e. CC E. b e. CC ( a + ( b ^ 2 ) ) = C ) |
47 |
1 5 11 20 38 46
|
syl32anc |
|- ( C e. CC -> -. E! a e. CC E. b e. CC ( a + ( b ^ 2 ) ) = C ) |