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 ⊢ ( 𝜑 → 𝐴 ∈ ℕ )
nna4b4nsq.b ⊢ ( 𝜑 → 𝐵 ∈ ℕ )
nna4b4nsq.c ⊢ ( 𝜑 → 𝐶 ∈ ℕ )
Assertion nna4b4nsq ( 𝜑 → ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) ≠ ( 𝐶 ↑ 2 ) )

Proof

Step Hyp Ref Expression
1 nna4b4nsq.a ⊢ ( 𝜑 → 𝐴 ∈ ℕ )
2 nna4b4nsq.b ⊢ ( 𝜑 → 𝐵 ∈ ℕ )
3 nna4b4nsq.c ⊢ ( 𝜑 → 𝐶 ∈ ℕ )
4 oveq1 ⊢ ( 𝑐 = 𝑓 → ( 𝑐 ↑ 2 ) = ( 𝑓 ↑ 2 ) )
5 4 eqeq2d ⊢ ( 𝑐 = 𝑓 → ( ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
6 5 anbi2d ⊢ ( 𝑐 = 𝑓 → ( ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ↔ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
7 6 anbi2d ⊢ ( 𝑐 = 𝑓 → ( ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
8 7 2rexbidv ⊢ ( 𝑐 = 𝑓 → ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ↔ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
9 oveq1 ⊢ ( 𝑐 = 𝑔 → ( 𝑐 ↑ 2 ) = ( 𝑔 ↑ 2 ) )
10 9 eqeq2d ⊢ ( 𝑐 = 𝑔 → ( ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑔 ↑ 2 ) ) )
11 10 anbi2d ⊢ ( 𝑐 = 𝑔 → ( ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ↔ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑔 ↑ 2 ) ) ) )
12 11 anbi2d ⊢ ( 𝑐 = 𝑔 → ( ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑔 ↑ 2 ) ) ) ) )
13 12 2rexbidv ⊢ ( 𝑐 = 𝑔 → ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ↔ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑔 ↑ 2 ) ) ) ) )
14 nnuz ⊢ ℕ = ( ℤ≥ ‘ 1 )
15 14 eqimssi ⊢ ℕ ⊆ ( ℤ≥ ‘ 1 )
16 15 a1i ⊢ ( 𝜑 → ℕ ⊆ ( ℤ≥ ‘ 1 ) )
17 breq2 ⊢ ( 𝑑 = ℎ → ( 2 ∥ 𝑑 ↔ 2 ∥ ℎ ) )
18 17 notbid ⊢ ( 𝑑 = ℎ → ( ¬ 2 ∥ 𝑑 ↔ ¬ 2 ∥ ℎ ) )
19 oveq1 ⊢ ( 𝑑 = ℎ → ( 𝑑 gcd 𝑒 ) = ( ℎ gcd 𝑒 ) )
20 19 eqeq1d ⊢ ( 𝑑 = ℎ → ( ( 𝑑 gcd 𝑒 ) = 1 ↔ ( ℎ gcd 𝑒 ) = 1 ) )
21 oveq1 ⊢ ( 𝑑 = ℎ → ( 𝑑 ↑ 4 ) = ( ℎ ↑ 4 ) )
22 21 oveq1d ⊢ ( 𝑑 = ℎ → ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( ℎ ↑ 4 ) + ( 𝑒 ↑ 4 ) ) )
23 22 eqeq1d ⊢ ( 𝑑 = ℎ → ( ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ↔ ( ( ℎ ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
24 20 23 anbi12d ⊢ ( 𝑑 = ℎ → ( ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ( ( ℎ gcd 𝑒 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
25 18 24 anbi12d ⊢ ( 𝑑 = ℎ → ( ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑒 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
26 oveq2 ⊢ ( 𝑒 = 𝑖 → ( ℎ gcd 𝑒 ) = ( ℎ gcd 𝑖 ) )
27 26 eqeq1d ⊢ ( 𝑒 = 𝑖 → ( ( ℎ gcd 𝑒 ) = 1 ↔ ( ℎ gcd 𝑖 ) = 1 ) )
28 oveq1 ⊢ ( 𝑒 = 𝑖 → ( 𝑒 ↑ 4 ) = ( 𝑖 ↑ 4 ) )
29 28 oveq2d ⊢ ( 𝑒 = 𝑖 → ( ( ℎ ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) )
30 29 eqeq1d ⊢ ( 𝑒 = 𝑖 → ( ( ( ℎ ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ↔ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) )
31 27 30 anbi12d ⊢ ( 𝑒 = 𝑖 → ( ( ( ℎ gcd 𝑒 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ↔ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
32 31 anbi2d ⊢ ( 𝑒 = 𝑖 → ( ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑒 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) )
33 25 32 cbvrex2vw ⊢ ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ↔ ∃ ℎ ∈ ℕ ∃ 𝑖 ∈ ℕ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) )
34 simplrl ⊢ ( ( ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) ∧ ( ℎ ∈ ℕ ∧ 𝑖 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) → ℎ ∈ ℕ )
35 simplrr ⊢ ( ( ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) ∧ ( ℎ ∈ ℕ ∧ 𝑖 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) → 𝑖 ∈ ℕ )
36 simpllr ⊢ ( ( ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) ∧ ( ℎ ∈ ℕ ∧ 𝑖 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) → 𝑓 ∈ ℕ )
37 simprl ⊢ ( ( ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) ∧ ( ℎ ∈ ℕ ∧ 𝑖 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) → ¬ 2 ∥ ℎ )
38 simprrl ⊢ ( ( ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) ∧ ( ℎ ∈ ℕ ∧ 𝑖 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) → ( ℎ gcd 𝑖 ) = 1 )
39 simprrr ⊢ ( ( ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) ∧ ( ℎ ∈ ℕ ∧ 𝑖 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) → ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) )
40 34 35 36 37 38 39 flt4lem7 ⊢ ( ( ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) ∧ ( ℎ ∈ ℕ ∧ 𝑖 ∈ ℕ ) ) ∧ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) → ∃ 𝑔 ∈ ℕ ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑔 ↑ 2 ) ) ) ∧ 𝑔 < 𝑓 ) )
41 40 ex ⊢ ( ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) ∧ ( ℎ ∈ ℕ ∧ 𝑖 ∈ ℕ ) ) → ( ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → ∃ 𝑔 ∈ ℕ ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑔 ↑ 2 ) ) ) ∧ 𝑔 < 𝑓 ) ) )
42 41 rexlimdvva ⊢ ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) → ( ∃ ℎ ∈ ℕ ∃ 𝑖 ∈ ℕ ( ¬ 2 ∥ ℎ ∧ ( ( ℎ gcd 𝑖 ) = 1 ∧ ( ( ℎ ↑ 4 ) + ( 𝑖 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → ∃ 𝑔 ∈ ℕ ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑔 ↑ 2 ) ) ) ∧ 𝑔 < 𝑓 ) ) )
43 33 42 biimtrid ⊢ ( ( 𝜑 ∧ 𝑓 ∈ ℕ ) → ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) → ∃ 𝑔 ∈ ℕ ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑔 ↑ 2 ) ) ) ∧ 𝑔 < 𝑓 ) ) )
44 43 impr ⊢ ( ( 𝜑 ∧ ( 𝑓 ∈ ℕ ∧ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑓 ↑ 2 ) ) ) ) ) → ∃ 𝑔 ∈ ℕ ( ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑔 ↑ 2 ) ) ) ∧ 𝑔 < 𝑓 ) )
45 8 13 16 44 infdesc ⊢ ( 𝜑 → { 𝑐 ∈ ℕ ∣ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) } = ∅ )
46 rabeq0 ⊢ ( { 𝑐 ∈ ℕ ∣ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) } = ∅ ↔ ∀ 𝑐 ∈ ℕ ¬ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
47 45 46 sylib ⊢ ( 𝜑 → ∀ 𝑐 ∈ ℕ ¬ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
48 ralnex ⊢ ( ∀ 𝑐 ∈ ℕ ¬ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ↔ ¬ ∃ 𝑐 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
49 47 48 sylib ⊢ ( 𝜑 → ¬ ∃ 𝑐 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
50 breq2 ⊢ ( 𝑑 = 𝑎 → ( 2 ∥ 𝑑 ↔ 2 ∥ 𝑎 ) )
51 50 notbid ⊢ ( 𝑑 = 𝑎 → ( ¬ 2 ∥ 𝑑 ↔ ¬ 2 ∥ 𝑎 ) )
52 oveq1 ⊢ ( 𝑑 = 𝑎 → ( 𝑑 gcd 𝑒 ) = ( 𝑎 gcd 𝑒 ) )
53 52 eqeq1d ⊢ ( 𝑑 = 𝑎 → ( ( 𝑑 gcd 𝑒 ) = 1 ↔ ( 𝑎 gcd 𝑒 ) = 1 ) )
54 oveq1 ⊢ ( 𝑑 = 𝑎 → ( 𝑑 ↑ 4 ) = ( 𝑎 ↑ 4 ) )
55 54 oveq1d ⊢ ( 𝑑 = 𝑎 → ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑎 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) )
56 55 eqeq1d ⊢ ( 𝑑 = 𝑎 → ( ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝑎 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
57 53 56 anbi12d ⊢ ( 𝑑 = 𝑎 → ( ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ↔ ( ( 𝑎 gcd 𝑒 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
58 51 57 anbi12d ⊢ ( 𝑑 = 𝑎 → ( ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑎 ∧ ( ( 𝑎 gcd 𝑒 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ) )
59 oveq2 ⊢ ( 𝑒 = 𝑏 → ( 𝑎 gcd 𝑒 ) = ( 𝑎 gcd 𝑏 ) )
60 59 eqeq1d ⊢ ( 𝑒 = 𝑏 → ( ( 𝑎 gcd 𝑒 ) = 1 ↔ ( 𝑎 gcd 𝑏 ) = 1 ) )
61 oveq1 ⊢ ( 𝑒 = 𝑏 → ( 𝑒 ↑ 4 ) = ( 𝑏 ↑ 4 ) )
62 61 oveq2d ⊢ ( 𝑒 = 𝑏 → ( ( 𝑎 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) )
63 62 eqeq1d ⊢ ( 𝑒 = 𝑏 → ( ( ( 𝑎 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
64 60 63 anbi12d ⊢ ( 𝑒 = 𝑏 → ( ( ( 𝑎 gcd 𝑒 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ↔ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
65 64 anbi2d ⊢ ( 𝑒 = 𝑏 → ( ( ¬ 2 ∥ 𝑎 ∧ ( ( 𝑎 gcd 𝑒 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑎 ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ) )
66 simprr ⊢ ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) → 𝑎 ∈ ℕ )
67 66 ad2antrr ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑎 ) → 𝑎 ∈ ℕ )
68 simprl ⊢ ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) → 𝑏 ∈ ℕ )
69 68 ad2antrr ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑎 ) → 𝑏 ∈ ℕ )
70 simpr ⊢ ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
71 70 anim1ci ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑎 ) → ( ¬ 2 ∥ 𝑎 ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
72 58 65 67 69 71 2rspcedvdw ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑎 ) → ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
73 breq2 ⊢ ( 𝑑 = 𝑏 → ( 2 ∥ 𝑑 ↔ 2 ∥ 𝑏 ) )
74 73 notbid ⊢ ( 𝑑 = 𝑏 → ( ¬ 2 ∥ 𝑑 ↔ ¬ 2 ∥ 𝑏 ) )
75 oveq1 ⊢ ( 𝑑 = 𝑏 → ( 𝑑 gcd 𝑒 ) = ( 𝑏 gcd 𝑒 ) )
76 75 eqeq1d ⊢ ( 𝑑 = 𝑏 → ( ( 𝑑 gcd 𝑒 ) = 1 ↔ ( 𝑏 gcd 𝑒 ) = 1 ) )
77 oveq1 ⊢ ( 𝑑 = 𝑏 → ( 𝑑 ↑ 4 ) = ( 𝑏 ↑ 4 ) )
78 77 oveq1d ⊢ ( 𝑑 = 𝑏 → ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑏 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) )
79 78 eqeq1d ⊢ ( 𝑑 = 𝑏 → ( ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝑏 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
80 76 79 anbi12d ⊢ ( 𝑑 = 𝑏 → ( ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ↔ ( ( 𝑏 gcd 𝑒 ) = 1 ∧ ( ( 𝑏 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
81 74 80 anbi12d ⊢ ( 𝑑 = 𝑏 → ( ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑏 ∧ ( ( 𝑏 gcd 𝑒 ) = 1 ∧ ( ( 𝑏 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ) )
82 oveq2 ⊢ ( 𝑒 = 𝑎 → ( 𝑏 gcd 𝑒 ) = ( 𝑏 gcd 𝑎 ) )
83 82 eqeq1d ⊢ ( 𝑒 = 𝑎 → ( ( 𝑏 gcd 𝑒 ) = 1 ↔ ( 𝑏 gcd 𝑎 ) = 1 ) )
84 oveq1 ⊢ ( 𝑒 = 𝑎 → ( 𝑒 ↑ 4 ) = ( 𝑎 ↑ 4 ) )
85 84 oveq2d ⊢ ( 𝑒 = 𝑎 → ( ( 𝑏 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( ( 𝑏 ↑ 4 ) + ( 𝑎 ↑ 4 ) ) )
86 85 eqeq1d ⊢ ( 𝑒 = 𝑎 → ( ( ( 𝑏 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( 𝑏 ↑ 4 ) + ( 𝑎 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
87 83 86 anbi12d ⊢ ( 𝑒 = 𝑎 → ( ( ( 𝑏 gcd 𝑒 ) = 1 ∧ ( ( 𝑏 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ↔ ( ( 𝑏 gcd 𝑎 ) = 1 ∧ ( ( 𝑏 ↑ 4 ) + ( 𝑎 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
88 87 anbi2d ⊢ ( 𝑒 = 𝑎 → ( ( ¬ 2 ∥ 𝑏 ∧ ( ( 𝑏 gcd 𝑒 ) = 1 ∧ ( ( 𝑏 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ↔ ( ¬ 2 ∥ 𝑏 ∧ ( ( 𝑏 gcd 𝑎 ) = 1 ∧ ( ( 𝑏 ↑ 4 ) + ( 𝑎 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ) )
89 68 ad2antrr ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → 𝑏 ∈ ℕ )
90 66 ad2antrr ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → 𝑎 ∈ ℕ )
91 simpr ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ¬ 2 ∥ 𝑏 )
92 89 nnzd ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → 𝑏 ∈ ℤ )
93 90 nnzd ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → 𝑎 ∈ ℤ )
94 92 93 gcdcomd ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( 𝑏 gcd 𝑎 ) = ( 𝑎 gcd 𝑏 ) )
95 simplrl ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( 𝑎 gcd 𝑏 ) = 1 )
96 94 95 eqtrd ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( 𝑏 gcd 𝑎 ) = 1 )
97 4nn0 ⊢ 4 ∈ ℕ0
98 97 a1i ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → 4 ∈ ℕ0 )
99 89 98 nnexpcld ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( 𝑏 ↑ 4 ) ∈ ℕ )
100 99 nncnd ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( 𝑏 ↑ 4 ) ∈ ℂ )
101 90 98 nnexpcld ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( 𝑎 ↑ 4 ) ∈ ℕ )
102 101 nncnd ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( 𝑎 ↑ 4 ) ∈ ℂ )
103 100 102 addcomd ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( ( 𝑏 ↑ 4 ) + ( 𝑎 ↑ 4 ) ) = ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) )
104 simplrr ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) )
105 103 104 eqtrd ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( ( 𝑏 ↑ 4 ) + ( 𝑎 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) )
106 91 96 105 jca32 ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ( ¬ 2 ∥ 𝑏 ∧ ( ( 𝑏 gcd 𝑎 ) = 1 ∧ ( ( 𝑏 ↑ 4 ) + ( 𝑎 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
107 81 88 89 90 106 2rspcedvdw ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ ¬ 2 ∥ 𝑏 ) → ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
108 66 ad2antrr ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ 2 ∥ 𝑎 ) → 𝑎 ∈ ℕ )
109 68 ad2antrr ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ 2 ∥ 𝑎 ) → 𝑏 ∈ ℕ )
110 simpr ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ 2 ∥ 𝑎 ) → 2 ∥ 𝑎 )
111 simplrl ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ 2 ∥ 𝑎 ) → ( 𝑎 gcd 𝑏 ) = 1 )
112 108 109 110 111 flt4lem2 ⊢ ( ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ∧ 2 ∥ 𝑎 ) → ¬ 2 ∥ 𝑏 )
113 112 ex ⊢ ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( 2 ∥ 𝑎 → ¬ 2 ∥ 𝑏 ) )
114 imor ⊢ ( ( 2 ∥ 𝑎 → ¬ 2 ∥ 𝑏 ) ↔ ( ¬ 2 ∥ 𝑎 ∨ ¬ 2 ∥ 𝑏 ) )
115 113 114 sylib ⊢ ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ( ¬ 2 ∥ 𝑎 ∨ ¬ 2 ∥ 𝑏 ) )
116 72 107 115 mpjaodan ⊢ ( ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) ∧ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) → ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
117 116 ex ⊢ ( ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) ∧ ( 𝑏 ∈ ℕ ∧ 𝑎 ∈ ℕ ) ) → ( ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) → ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ) )
118 117 rexlimdvva ⊢ ( ( 𝜑 ∧ 𝑐 ∈ ℕ ) → ( ∃ 𝑏 ∈ ℕ ∃ 𝑎 ∈ ℕ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) → ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ) )
119 118 reximdva ⊢ ( 𝜑 → ( ∃ 𝑐 ∈ ℕ ∃ 𝑏 ∈ ℕ ∃ 𝑎 ∈ ℕ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) → ∃ 𝑐 ∈ ℕ ∃ 𝑑 ∈ ℕ ∃ 𝑒 ∈ ℕ ( ¬ 2 ∥ 𝑑 ∧ ( ( 𝑑 gcd 𝑒 ) = 1 ∧ ( ( 𝑑 ↑ 4 ) + ( 𝑒 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) ) )
120 49 119 mtod ⊢ ( 𝜑 → ¬ ∃ 𝑐 ∈ ℕ ∃ 𝑏 ∈ ℕ ∃ 𝑎 ∈ ℕ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
121 rexcom13 ⊢ ( ∃ 𝑐 ∈ ℕ ∃ 𝑏 ∈ ℕ ∃ 𝑎 ∈ ℕ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ↔ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ∃ 𝑐 ∈ ℕ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
122 120 121 sylnib ⊢ ( 𝜑 → ¬ ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ∃ 𝑐 ∈ ℕ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
123 oveq1 ⊢ ( 𝑎 = ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) → ( 𝑎 gcd 𝑏 ) = ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd 𝑏 ) )
124 123 eqeq1d ⊢ ( 𝑎 = ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) → ( ( 𝑎 gcd 𝑏 ) = 1 ↔ ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd 𝑏 ) = 1 ) )
125 oveq1 ⊢ ( 𝑎 = ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) → ( 𝑎 ↑ 4 ) = ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) )
126 125 oveq1d ⊢ ( 𝑎 = ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) → ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( 𝑏 ↑ 4 ) ) )
127 126 eqeq1d ⊢ ( 𝑎 = ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) → ( ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
128 124 127 anbi12d ⊢ ( 𝑎 = ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) → ( ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ↔ ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd 𝑏 ) = 1 ∧ ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) ) )
129 oveq2 ⊢ ( 𝑏 = ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) → ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd 𝑏 ) = ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ) )
130 129 eqeq1d ⊢ ( 𝑏 = ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) → ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd 𝑏 ) = 1 ↔ ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ) = 1 ) )
131 oveq1 ⊢ ( 𝑏 = ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) → ( 𝑏 ↑ 4 ) = ( ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) )
132 131 oveq2d ⊢ ( 𝑏 = ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) → ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) ) )
133 132 eqeq1d ⊢ ( 𝑏 = ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) → ( ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
134 130 133 anbi12d ⊢ ( 𝑏 = ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) → ( ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd 𝑏 ) = 1 ∧ ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 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 ↑ 2 ) ) ) )
135 oveq1 ⊢ ( 𝑐 = ( 𝐶 / ( ( 𝐴 gcd 𝐵 ) ↑ 2 ) ) → ( 𝑐 ↑ 2 ) = ( ( 𝐶 / ( ( 𝐴 gcd 𝐵 ) ↑ 2 ) ) ↑ 2 ) )
136 135 eqeq2d ⊢ ( 𝑐 = ( 𝐶 / ( ( 𝐴 gcd 𝐵 ) ↑ 2 ) ) → ( ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ↔ ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) ) = ( ( 𝐶 / ( ( 𝐴 gcd 𝐵 ) ↑ 2 ) ) ↑ 2 ) ) )
137 136 anbi2d ⊢ ( 𝑐 = ( 𝐶 / ( ( 𝐴 gcd 𝐵 ) ↑ 2 ) ) → ( ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ) = 1 ∧ ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( ( 𝐵 / ( 𝐴 gcd 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 ) ) ) )
138 1 adantr ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → 𝐴 ∈ ℕ )
139 2 adantr ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → 𝐵 ∈ ℕ )
140 3 adantr ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → 𝐶 ∈ ℕ )
141 simpr ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) )
142 138 139 140 141 flt4lem6 ⊢ ( ( 𝜑 ∧ ( ( 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 ) ) )
143 142 simpld ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ∈ ℕ ∧ ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ∈ ℕ ∧ ( 𝐶 / ( ( 𝐴 gcd 𝐵 ) ↑ 2 ) ) ∈ ℕ ) )
144 143 simp1d ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ∈ ℕ )
145 143 simp2d ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ∈ ℕ )
146 143 simp3d ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → ( 𝐶 / ( ( 𝐴 gcd 𝐵 ) ↑ 2 ) ) ∈ ℕ )
147 1 nnzd ⊢ ( 𝜑 → 𝐴 ∈ ℤ )
148 147 adantr ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → 𝐴 ∈ ℤ )
149 2 nnzd ⊢ ( 𝜑 → 𝐵 ∈ ℤ )
150 149 adantr ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → 𝐵 ∈ ℤ )
151 2 nnne0d ⊢ ( 𝜑 → 𝐵 ≠ 0 )
152 151 adantr ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → 𝐵 ≠ 0 )
153 divgcdcoprm0 ⊢ ( ( 𝐴 ∈ ℤ ∧ 𝐵 ∈ ℤ ∧ 𝐵 ≠ 0 ) → ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ) = 1 )
154 148 150 152 153 syl3anc ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) gcd ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ) = 1 )
155 142 simprd ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → ( ( ( 𝐴 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) + ( ( 𝐵 / ( 𝐴 gcd 𝐵 ) ) ↑ 4 ) ) = ( ( 𝐶 / ( ( 𝐴 gcd 𝐵 ) ↑ 2 ) ) ↑ 2 ) )
156 154 155 jca ⊢ ( ( 𝜑 ∧ ( ( 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 ) ) )
157 128 134 137 144 145 146 156 3rspcedvdw ⊢ ( ( 𝜑 ∧ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) ) → ∃ 𝑎 ∈ ℕ ∃ 𝑏 ∈ ℕ ∃ 𝑐 ∈ ℕ ( ( 𝑎 gcd 𝑏 ) = 1 ∧ ( ( 𝑎 ↑ 4 ) + ( 𝑏 ↑ 4 ) ) = ( 𝑐 ↑ 2 ) ) )
158 122 157 mtand ⊢ ( 𝜑 → ¬ ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) = ( 𝐶 ↑ 2 ) )
159 158 neqned ⊢ ( 𝜑 → ( ( 𝐴 ↑ 4 ) + ( 𝐵 ↑ 4 ) ) ≠ ( 𝐶 ↑ 2 ) )