Metamath Proof Explorer


Theorem nna4b4nsq

Description: Strengthening of Fermat's last theorem for exponent 4, where the sum is only assumed to be a square. (Contributed by SN, 23-Aug-2024)

Ref Expression
Hypotheses nna4b4nsq.a ( 𝜑𝐴 ∈ ℕ )
nna4b4nsq.b ( 𝜑𝐵 ∈ ℕ )
nna4b4nsq.c ( 𝜑𝐶 ∈ ℕ )
Assertion nna4b4nsq ( 𝜑 → ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) ≠ ( 𝐶 ↑ 2 ) )

Proof

Step Hyp Ref Expression
1 nna4b4nsq.a ( 𝜑𝐴 ∈ ℕ )
2 nna4b4nsq.b ( 𝜑𝐵 ∈ ℕ )
3 nna4b4nsq.c ( 𝜑𝐶 ∈ ℕ )
4 oveq1 ( 𝑎 = 𝐴 → ( 𝑎 ↑ 4 ) = ( 𝐴 ↑ 4 ) )
5 4 oveq1d ( 𝑎 = 𝐴 → ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( ( 𝐴 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) )
6 5 eqeq1d ( 𝑎 = 𝐴 → ( ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝐴 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
7 oveq1 ( 𝑏 = 𝐵 → ( 𝑏 ↑ 4 ) = ( 𝐵 ↑ 4 ) )
8 7 oveq2d ( 𝑏 = 𝐵 → ( ( 𝐴 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) )
9 8 eqeq1d ( 𝑏 = 𝐵 → ( ( ( 𝐴 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
10 1 ad2antrr ( ( ( 𝜑𝑐 ∈ ℕ ) ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) → 𝐴 ∈ ℕ )
11 2 ad2antrr ( ( ( 𝜑𝑐 ∈ ℕ ) ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) → 𝐵 ∈ ℕ )
12 simpr ( ( ( 𝜑𝑐 ∈ ℕ ) ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) → ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) )
13 6 9 10 11 12 2rspcedvdw ( ( ( 𝜑𝑐 ∈ ℕ ) ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) → ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) )
14 13 ex ( ( 𝜑𝑐 ∈ ℕ ) → ( ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) → ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
15 14 ss2rabdv ( 𝜑 → { 𝑐 ∈ ℕ ∣ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } ⊆ { 𝑐 ∈ ℕ ∣ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } )
16 oveq1 ( 𝑓 = 𝑖 → ( 𝑓 ↑ 2 ) = ( 𝑖 ↑ 2 ) )
17 16 eqeq2d ( 𝑓 = 𝑖 → ( ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ↔ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) )
18 17 anbi2d ( 𝑓 = 𝑖 → ( ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) )
19 18 anbi2d ( 𝑓 = 𝑖 → ( ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) )
20 19 2rexbidv ( 𝑓 = 𝑖 → ( ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) )
21 oveq1 ( 𝑓 = 𝑙 → ( 𝑓 ↑ 2 ) = ( 𝑙 ↑ 2 ) )
22 21 eqeq2d ( 𝑓 = 𝑙 → ( ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ↔ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑙 ↑ 2 ) ) )
23 22 anbi2d ( 𝑓 = 𝑙 → ( ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑙 ↑ 2 ) ) ) )
24 23 anbi2d ( 𝑓 = 𝑙 → ( ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑙 ↑ 2 ) ) ) ) )
25 24 2rexbidv ( 𝑓 = 𝑙 → ( ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑙 ↑ 2 ) ) ) ) )
26 nnuz ℕ = ( ℤ ‘ 1 )
27 26 eqimssi ℕ ⊆ ( ℤ ‘ 1 )
28 27 a1i ( 𝜑 → ℕ ⊆ ( ℤ ‘ 1 ) )
29 breq2 ( 𝑔 = 𝑗 → ( 2 ∥ 𝑔 ↔ 2 ∥ 𝑗 ) )
30 29 notbid ( 𝑔 = 𝑗 → ( ¬ 2 ∥ 𝑔 ↔ ¬ 2 ∥ 𝑗 ) )
31 oveq1 ( 𝑔 = 𝑗 → ( 𝑔 gcd ) = ( 𝑗 gcd ) )
32 31 eqeq1d ( 𝑔 = 𝑗 → ( ( 𝑔 gcd ) = 1 ↔ ( 𝑗 gcd ) = 1 ) )
33 oveq1 ( 𝑔 = 𝑗 → ( 𝑔 ↑ 4 ) = ( 𝑗 ↑ 4 ) )
34 33 oveq1d ( 𝑔 = 𝑗 → ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( ( 𝑗 ↑ 4 ) + ( ↑ 4 ) ) )
35 34 eqeq1d ( 𝑔 = 𝑗 → ( ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ↔ ( ( 𝑗 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) )
36 32 35 anbi12d ( 𝑔 = 𝑗 → ( ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ↔ ( ( 𝑗 gcd ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) )
37 30 36 anbi12d ( 𝑔 = 𝑗 → ( ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) )
38 oveq2 ( = 𝑘 → ( 𝑗 gcd ) = ( 𝑗 gcd 𝑘 ) )
39 38 eqeq1d ( = 𝑘 → ( ( 𝑗 gcd ) = 1 ↔ ( 𝑗 gcd 𝑘 ) = 1 ) )
40 oveq1 ( = 𝑘 → ( ↑ 4 ) = ( 𝑘 ↑ 4 ) )
41 40 oveq2d ( = 𝑘 → ( ( 𝑗 ↑ 4 ) + ( ↑ 4 ) ) = ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) )
42 41 eqeq1d ( = 𝑘 → ( ( ( 𝑗 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ↔ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) )
43 39 42 anbi12d ( = 𝑘 → ( ( ( 𝑗 gcd ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ↔ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) )
44 43 anbi2d ( = 𝑘 → ( ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) )
45 37 44 cbvrex2vw ( ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ↔ ∃ 𝑗 ∈ ℕ ∃ 𝑘 ∈ ℕ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) )
46 simplrl ( ( ( ( 𝜑𝑖 ∈ ℕ ) ∧ ( 𝑗 ∈ ℕ ∧ 𝑘 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) → 𝑗 ∈ ℕ )
47 simplrr ( ( ( ( 𝜑𝑖 ∈ ℕ ) ∧ ( 𝑗 ∈ ℕ ∧ 𝑘 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) → 𝑘 ∈ ℕ )
48 simpllr ( ( ( ( 𝜑𝑖 ∈ ℕ ) ∧ ( 𝑗 ∈ ℕ ∧ 𝑘 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) → 𝑖 ∈ ℕ )
49 simprl ( ( ( ( 𝜑𝑖 ∈ ℕ ) ∧ ( 𝑗 ∈ ℕ ∧ 𝑘 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) → ¬ 2 ∥ 𝑗 )
50 simprrl ( ( ( ( 𝜑𝑖 ∈ ℕ ) ∧ ( 𝑗 ∈ ℕ ∧ 𝑘 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) → ( 𝑗 gcd 𝑘 ) = 1 )
51 simprrr ( ( ( ( 𝜑𝑖 ∈ ℕ ) ∧ ( 𝑗 ∈ ℕ ∧ 𝑘 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) → ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) )
52 46 47 48 49 50 51 flt4lem7 ( ( ( ( 𝜑𝑖 ∈ ℕ ) ∧ ( 𝑗 ∈ ℕ ∧ 𝑘 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) → ∃ 𝑙 ∈ ℕ ( ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑙 ↑ 2 ) ) ) ∧ 𝑙 < 𝑖 ) )
53 52 ex ( ( ( 𝜑𝑖 ∈ ℕ ) ∧ ( 𝑗 ∈ ℕ ∧ 𝑘 ∈ ℕ ) ) → ( ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) → ∃ 𝑙 ∈ ℕ ( ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑙 ↑ 2 ) ) ) ∧ 𝑙 < 𝑖 ) ) )
54 53 rexlimdvva ( ( 𝜑𝑖 ∈ ℕ ) → ( ∃ 𝑗 ∈ ℕ ∃ 𝑘 ∈ ℕ ( ¬ 2 ∥ 𝑗 ∧ ( ( 𝑗 gcd 𝑘 ) = 1 ∧ ( ( 𝑗 ↑ 4 ) + ( 𝑘 ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) → ∃ 𝑙 ∈ ℕ ( ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑙 ↑ 2 ) ) ) ∧ 𝑙 < 𝑖 ) ) )
55 45 54 syl5bi ( ( 𝜑𝑖 ∈ ℕ ) → ( ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) → ∃ 𝑙 ∈ ℕ ( ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑙 ↑ 2 ) ) ) ∧ 𝑙 < 𝑖 ) ) )
56 55 impr ( ( 𝜑 ∧ ( 𝑖 ∈ ℕ ∧ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑖 ↑ 2 ) ) ) ) ) → ∃ 𝑙 ∈ ℕ ( ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑙 ↑ 2 ) ) ) ∧ 𝑙 < 𝑖 ) )
57 20 25 28 56 infdesc ( 𝜑 → { 𝑓 ∈ ℕ ∣ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) } = ∅ )
58 breq2 ( 𝑔 = 𝑑 → ( 2 ∥ 𝑔 ↔ 2 ∥ 𝑑 ) )
59 58 notbid ( 𝑔 = 𝑑 → ( ¬ 2 ∥ 𝑔 ↔ ¬ 2 ∥ 𝑑 ) )
60 oveq1 ( 𝑔 = 𝑑 → ( 𝑔 gcd ) = ( 𝑑 gcd ) )
61 60 eqeq1d ( 𝑔 = 𝑑 → ( ( 𝑔 gcd ) = 1 ↔ ( 𝑑 gcd ) = 1 ) )
62 oveq1 ( 𝑔 = 𝑑 → ( 𝑔 ↑ 4 ) = ( 𝑑 ↑ 4 ) )
63 62 oveq1d ( 𝑔 = 𝑑 → ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( ( 𝑑 ↑ 4 ) + ( ↑ 4 ) ) )
64 63 eqeq1d ( 𝑔 = 𝑑 → ( ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ↔ ( ( 𝑑 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
65 61 64 anbi12d ( 𝑔 = 𝑑 → ( ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ( ( 𝑑 gcd ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
66 59 65 anbi12d ( 𝑔 = 𝑑 → ( ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
67 oveq2 ( = 𝑒 → ( 𝑑 gcd ) = ( 𝑑 gcd 𝑒 ) )
68 67 eqeq1d ( = 𝑒 → ( ( 𝑑 gcd ) = 1 ↔ ( 𝑑 gcd 𝑒 ) = 1 ) )
69 oveq1 ( = 𝑒 → ( ↑ 4 ) = ( 𝑒 ↑ 4 ) )
70 69 oveq2d ( = 𝑒 → ( ( 𝑑 ↑ 4 ) + ( ↑ 4 ) ) = ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) )
71 70 eqeq1d ( = 𝑒 → ( ( ( 𝑑 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ↔ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
72 68 71 anbi12d ( = 𝑒 → ( ( ( 𝑑 gcd ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
73 72 anbi2d ( = 𝑒 → ( ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
74 simprl ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) → 𝑑 ∈ ℕ )
75 74 ad2antrr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑑 ) → 𝑑 ∈ ℕ )
76 simprr ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) → 𝑒 ∈ ℕ )
77 76 ad2antrr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑑 ) → 𝑒 ∈ ℕ )
78 simpr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑑 ) → ¬ 2 ∥ 𝑑 )
79 simplr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑑 ) → ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
80 78 79 jca ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑑 ) → ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
81 66 73 75 77 80 2rspcedvdw ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑑 ) → ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
82 breq2 ( 𝑔 = 𝑒 → ( 2 ∥ 𝑔 ↔ 2 ∥ 𝑒 ) )
83 82 notbid ( 𝑔 = 𝑒 → ( ¬ 2 ∥ 𝑔 ↔ ¬ 2 ∥ 𝑒 ) )
84 oveq1 ( 𝑔 = 𝑒 → ( 𝑔 gcd ) = ( 𝑒 gcd ) )
85 84 eqeq1d ( 𝑔 = 𝑒 → ( ( 𝑔 gcd ) = 1 ↔ ( 𝑒 gcd ) = 1 ) )
86 oveq1 ( 𝑔 = 𝑒 → ( 𝑔 ↑ 4 ) = ( 𝑒 ↑ 4 ) )
87 86 oveq1d ( 𝑔 = 𝑒 → ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( ( 𝑒 ↑ 4 ) + ( ↑ 4 ) ) )
88 87 eqeq1d ( 𝑔 = 𝑒 → ( ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ↔ ( ( 𝑒 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
89 85 88 anbi12d ( 𝑔 = 𝑒 → ( ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ( ( 𝑒 gcd ) = 1 ∧ ( ( 𝑒 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
90 83 89 anbi12d ( 𝑔 = 𝑒 → ( ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑒 ∧ ( ( 𝑒 gcd ) = 1 ∧ ( ( 𝑒 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
91 oveq2 ( = 𝑑 → ( 𝑒 gcd ) = ( 𝑒 gcd 𝑑 ) )
92 91 eqeq1d ( = 𝑑 → ( ( 𝑒 gcd ) = 1 ↔ ( 𝑒 gcd 𝑑 ) = 1 ) )
93 oveq1 ( = 𝑑 → ( ↑ 4 ) = ( 𝑑 ↑ 4 ) )
94 93 oveq2d ( = 𝑑 → ( ( 𝑒 ↑ 4 ) + ( ↑ 4 ) ) = ( ( 𝑒 ↑ 4 ) + ( 𝑑 ↑ 4 ) ) )
95 94 eqeq1d ( = 𝑑 → ( ( ( 𝑒 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ↔ ( ( 𝑒 ↑ 4 ) + ( 𝑑 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
96 92 95 anbi12d ( = 𝑑 → ( ( ( 𝑒 gcd ) = 1 ∧ ( ( 𝑒 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ( ( 𝑒 gcd 𝑑 ) = 1 ∧ ( ( 𝑒 ↑ 4 ) + ( 𝑑 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
97 96 anbi2d ( = 𝑑 → ( ( ¬ 2 ∥ 𝑒 ∧ ( ( 𝑒 gcd ) = 1 ∧ ( ( 𝑒 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑒 ∧ ( ( 𝑒 gcd 𝑑 ) = 1 ∧ ( ( 𝑒 ↑ 4 ) + ( 𝑑 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
98 76 ad2antrr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → 𝑒 ∈ ℕ )
99 74 ad2antrr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → 𝑑 ∈ ℕ )
100 simpr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ¬ 2 ∥ 𝑒 )
101 98 nnzd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → 𝑒 ∈ ℤ )
102 99 nnzd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → 𝑑 ∈ ℤ )
103 101 102 gcdcomd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( 𝑒 gcd 𝑑 ) = ( 𝑑 gcd 𝑒 ) )
104 simplrl ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( 𝑑 gcd 𝑒 ) = 1 )
105 103 104 eqtrd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( 𝑒 gcd 𝑑 ) = 1 )
106 4nn0 4 ∈ ℕ0
107 106 a1i ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → 4 ∈ ℕ0 )
108 98 107 nnexpcld ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( 𝑒 ↑ 4 ) ∈ ℕ )
109 108 nncnd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( 𝑒 ↑ 4 ) ∈ ℂ )
110 99 107 nnexpcld ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( 𝑑 ↑ 4 ) ∈ ℕ )
111 110 nncnd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( 𝑑 ↑ 4 ) ∈ ℂ )
112 109 111 addcomd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( ( 𝑒 ↑ 4 ) + ( 𝑑 ↑ 4 ) ) = ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) )
113 simplrr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) )
114 112 113 eqtrd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( ( 𝑒 ↑ 4 ) + ( 𝑑 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) )
115 100 105 114 jca32 ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ( ¬ 2 ∥ 𝑒 ∧ ( ( 𝑒 gcd 𝑑 ) = 1 ∧ ( ( 𝑒 ↑ 4 ) + ( 𝑑 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
116 90 97 98 99 115 2rspcedvdw ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑒 ) → ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
117 74 ad2antrr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → 𝑑 ∈ ℕ )
118 117 nnsqcld ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( 𝑑 ↑ 2 ) ∈ ℕ )
119 76 ad2antrr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → 𝑒 ∈ ℕ )
120 119 nnsqcld ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( 𝑒 ↑ 2 ) ∈ ℕ )
121 simp-4r ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → 𝑓 ∈ ℕ )
122 2z 2 ∈ ℤ
123 simplrl ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → 𝑑 ∈ ℕ )
124 123 nnzd ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → 𝑑 ∈ ℤ )
125 2nn 2 ∈ ℕ
126 125 a1i ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → 2 ∈ ℕ )
127 dvdsexp2im ( ( 2 ∈ ℤ ∧ 𝑑 ∈ ℤ ∧ 2 ∈ ℕ ) → ( 2 ∥ 𝑑 → 2 ∥ ( 𝑑 ↑ 2 ) ) )
128 122 124 126 127 mp3an2i ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → ( 2 ∥ 𝑑 → 2 ∥ ( 𝑑 ↑ 2 ) ) )
129 128 imp ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → 2 ∥ ( 𝑑 ↑ 2 ) )
130 2nn0 2 ∈ ℕ0
131 130 a1i ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → 2 ∈ ℕ0 )
132 117 nncnd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → 𝑑 ∈ ℂ )
133 132 flt4lem ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( 𝑑 ↑ 4 ) = ( ( 𝑑 ↑ 2 ) ↑ 2 ) )
134 119 nncnd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → 𝑒 ∈ ℂ )
135 134 flt4lem ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( 𝑒 ↑ 4 ) = ( ( 𝑒 ↑ 2 ) ↑ 2 ) )
136 133 135 oveq12d ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( ( 𝑑 ↑ 2 ) ↑ 2 ) + ( ( 𝑒 ↑ 2 ) ↑ 2 ) ) )
137 simplrr ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) )
138 136 137 eqtr3d ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( ( ( 𝑑 ↑ 2 ) ↑ 2 ) + ( ( 𝑒 ↑ 2 ) ↑ 2 ) ) = ( 𝑓 ↑ 2 ) )
139 simplrl ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( 𝑑 gcd 𝑒 ) = 1 )
140 125 a1i ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → 2 ∈ ℕ )
141 rppwr ( ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ∧ 2 ∈ ℕ ) → ( ( 𝑑 gcd 𝑒 ) = 1 → ( ( 𝑑 ↑ 2 ) gcd ( 𝑒 ↑ 2 ) ) = 1 ) )
142 117 119 140 141 syl3anc ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( ( 𝑑 gcd 𝑒 ) = 1 → ( ( 𝑑 ↑ 2 ) gcd ( 𝑒 ↑ 2 ) ) = 1 ) )
143 139 142 mpd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( ( 𝑑 ↑ 2 ) gcd ( 𝑒 ↑ 2 ) ) = 1 )
144 118 120 121 131 138 143 fltaccoprm ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( ( 𝑑 ↑ 2 ) gcd 𝑓 ) = 1 )
145 118 120 121 129 144 138 flt4lem2 ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ¬ 2 ∥ ( 𝑒 ↑ 2 ) )
146 119 nnzd ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → 𝑒 ∈ ℤ )
147 dvdsexp2im ( ( 2 ∈ ℤ ∧ 𝑒 ∈ ℤ ∧ 2 ∈ ℕ ) → ( 2 ∥ 𝑒 → 2 ∥ ( 𝑒 ↑ 2 ) ) )
148 122 146 140 147 mp3an2i ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ( 2 ∥ 𝑒 → 2 ∥ ( 𝑒 ↑ 2 ) ) )
149 145 148 mtod ( ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ∧ 2 ∥ 𝑑 ) → ¬ 2 ∥ 𝑒 )
150 149 ex ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → ( 2 ∥ 𝑑 → ¬ 2 ∥ 𝑒 ) )
151 imor ( ( 2 ∥ 𝑑 → ¬ 2 ∥ 𝑒 ) ↔ ( ¬ 2 ∥ 𝑑 ∨ ¬ 2 ∥ 𝑒 ) )
152 150 151 sylib ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → ( ¬ 2 ∥ 𝑑 ∨ ¬ 2 ∥ 𝑒 ) )
153 81 116 152 mpjaodan ( ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
154 153 ex ( ( ( 𝜑𝑓 ∈ ℕ ) ∧ ( 𝑑 ∈ ℕ ∧ 𝑒 ∈ ℕ ) ) → ( ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) → ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
155 154 rexlimdvva ( ( 𝜑𝑓 ∈ ℕ ) → ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) → ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
156 155 reximdva ( 𝜑 → ( ∃ 𝑓 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) → ∃ 𝑓 ∈ ℕ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
157 156 con3d ( 𝜑 → ( ¬ ∃ 𝑓 ∈ ℕ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → ¬ ∃ 𝑓 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
158 ralnex ( ∀ 𝑓 ∈ ℕ ¬ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ¬ ∃ 𝑓 ∈ ℕ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
159 ralnex ( ∀ 𝑓 ∈ ℕ ¬ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ¬ ∃ 𝑓 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
160 157 158 159 3imtr4g ( 𝜑 → ( ∀ 𝑓 ∈ ℕ ¬ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → ∀ 𝑓 ∈ ℕ ¬ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
161 rabeq0 ( { 𝑓 ∈ ℕ ∣ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) } = ∅ ↔ ∀ 𝑓 ∈ ℕ ¬ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
162 rabeq0 ( { 𝑓 ∈ ℕ ∣ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) } = ∅ ↔ ∀ 𝑓 ∈ ℕ ¬ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
163 160 161 162 3imtr4g ( 𝜑 → ( { 𝑓 ∈ ℕ ∣ ∃ 𝑔 ∈ ℕ ∃ ∈ ℕ ( ¬ 2 ∥ 𝑔 ∧ ( ( 𝑔 gcd ) = 1 ∧ ( ( 𝑔 ↑ 4 ) + ( ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) } = ∅ → { 𝑓 ∈ ℕ ∣ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) } = ∅ ) )
164 57 163 mpd ( 𝜑 → { 𝑓 ∈ ℕ ∣ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) } = ∅ )
165 oveq1 ( 𝑓 = ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) → ( 𝑓 ↑ 2 ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) )
166 165 eqeq2d ( 𝑓 = ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) → ( ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ↔ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) )
167 166 anbi2d ( 𝑓 = ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) → ( ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) ) )
168 oveq1 ( 𝑑 = ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) → ( 𝑑 gcd 𝑒 ) = ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd 𝑒 ) )
169 168 eqeq1d ( 𝑑 = ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) → ( ( 𝑑 gcd 𝑒 ) = 1 ↔ ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd 𝑒 ) = 1 ) )
170 oveq1 ( 𝑑 = ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) → ( 𝑑 ↑ 4 ) = ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) )
171 170 oveq1d ( 𝑑 = ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) → ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( 𝑒 ↑ 4 ) ) )
172 171 eqeq1d ( 𝑑 = ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) → ( ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ↔ ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) )
173 169 172 anbi12d ( 𝑑 = ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) → ( ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) ↔ ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd 𝑒 ) = 1 ∧ ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) ) )
174 oveq2 ( 𝑒 = ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) → ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd 𝑒 ) = ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ) )
175 174 eqeq1d ( 𝑒 = ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) → ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd 𝑒 ) = 1 ↔ ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ) = 1 ) )
176 oveq1 ( 𝑒 = ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) → ( 𝑒 ↑ 4 ) = ( ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) )
177 176 oveq2d ( 𝑒 = ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) → ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) ) )
178 177 eqeq1d ( 𝑒 = ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) → ( ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ↔ ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) )
179 175 178 anbi12d ( 𝑒 = ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) → ( ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd 𝑒 ) = 1 ∧ ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) ↔ ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ) = 1 ∧ ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) ) )
180 simplrr ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → 𝑎 ∈ ℕ )
181 simprl ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → 𝑏 ∈ ℕ )
182 simplrl ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → 𝑐 ∈ ℕ )
183 simprr ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) )
184 180 181 182 183 flt4lem6 ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ∈ ℕ ∧ ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ∈ ℕ ∧ ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ∈ ℕ ) ∧ ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) )
185 184 simpld ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ∈ ℕ ∧ ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ∈ ℕ ∧ ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ∈ ℕ ) )
186 185 simp3d ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ∈ ℕ )
187 185 simp1d ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ∈ ℕ )
188 185 simp2d ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ∈ ℕ )
189 180 nnzd ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → 𝑎 ∈ ℤ )
190 181 nnzd ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → 𝑏 ∈ ℤ )
191 181 nnne0d ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → 𝑏 ≠ 0 )
192 divgcdcoprm0 ( ( 𝑎 ∈ ℤ ∧ 𝑏 ∈ ℤ ∧ 𝑏 ≠ 0 ) → ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ) = 1 )
193 189 190 191 192 syl3anc ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ) = 1 )
194 184 simprd ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) )
195 193 194 jca ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) gcd ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ) = 1 ∧ ( ( ( 𝑎 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) + ( ( 𝑏 / ( 𝑎 gcd 𝑏 ) ) ↑ 4 ) ) = ( ( 𝑐 / ( ( 𝑎 gcd 𝑏 ) ↑ 2 ) ) ↑ 2 ) ) )
196 167 173 179 186 187 188 195 3rspcedvdw ( ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( 𝑏 ∈ ℕ ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ∃ 𝑓 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
197 196 rexlimdvaa ( ( 𝜑 ∧ ( 𝑐 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) → ( ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) → ∃ 𝑓 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
198 197 rexlimdvva ( 𝜑 → ( ∃ 𝑐 ∈ ℕ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) → ∃ 𝑓 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
199 198 con3d ( 𝜑 → ( ¬ ∃ 𝑓 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) → ¬ ∃ 𝑐 ∈ ℕ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
200 ralnex ( ∀ 𝑐 ∈ ℕ ¬ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ¬ ∃ 𝑐 ∈ ℕ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) )
201 199 159 200 3imtr4g ( 𝜑 → ( ∀ 𝑓 ∈ ℕ ¬ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) → ∀ 𝑐 ∈ ℕ ¬ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
202 rabeq0 ( { 𝑐 ∈ ℕ ∣ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } = ∅ ↔ ∀ 𝑐 ∈ ℕ ¬ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) )
203 201 162 202 3imtr4g ( 𝜑 → ( { 𝑓 ∈ ℕ ∣ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) } = ∅ → { 𝑐 ∈ ℕ ∣ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } = ∅ ) )
204 164 203 mpd ( 𝜑 → { 𝑐 ∈ ℕ ∣ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } = ∅ )
205 sseq0 ( ( { 𝑐 ∈ ℕ ∣ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } ⊆ { 𝑐 ∈ ℕ ∣ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } ∧ { 𝑐 ∈ ℕ ∣ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } = ∅ ) → { 𝑐 ∈ ℕ ∣ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } = ∅ )
206 15 204 205 syl2anc ( 𝜑 → { 𝑐 ∈ ℕ ∣ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } = ∅ )
207 rabeq0 ( { 𝑐 ∈ ℕ ∣ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) } = ∅ ↔ ∀ 𝑐 ∈ ℕ ¬ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) )
208 206 207 sylib ( 𝜑 → ∀ 𝑐 ∈ ℕ ¬ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) )
209 oveq1 ( 𝑐 = 𝐶 → ( 𝑐 ↑ 2 ) = ( 𝐶 ↑ 2 ) )
210 209 eqeq2d ( 𝑐 = 𝐶 → ( ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) )
211 210 necon3bbid ( 𝑐 = 𝐶 → ( ¬ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) ≠ ( 𝐶 ↑ 2 ) ) )
212 211 rspcv ( 𝐶 ∈ ℕ → ( ∀ 𝑐 ∈ ℕ ¬ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) → ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) ≠ ( 𝐶 ↑ 2 ) ) )
213 3 208 212 sylc ( 𝜑 → ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) ≠ ( 𝐶 ↑ 2 ) )