Metamath Proof Explorer


Theorem oexpreposd

Description: Lemma for dffltz . TODO-SN?: This can be used to show exp11d holds for all integers when the exponent is odd. The more standard -. 2 || M should be used. (Contributed by SN, 4-Mar-2023)

Ref Expression
Hypotheses oexpreposd.n ( 𝜑𝑁 ∈ ℝ )
oexpreposd.m ( 𝜑𝑀 ∈ ℕ )
oexpreposd.1 ( 𝜑 → ¬ ( 𝑀 / 2 ) ∈ ℕ )
Assertion oexpreposd ( 𝜑 → ( 0 < 𝑁 ↔ 0 < ( 𝑁𝑀 ) ) )

Proof

Step Hyp Ref Expression
1 oexpreposd.n ( 𝜑𝑁 ∈ ℝ )
2 oexpreposd.m ( 𝜑𝑀 ∈ ℕ )
3 oexpreposd.1 ( 𝜑 → ¬ ( 𝑀 / 2 ) ∈ ℕ )
4 1 adantr ( ( 𝜑 ∧ 0 < 𝑁 ) → 𝑁 ∈ ℝ )
5 2 nnzd ( 𝜑𝑀 ∈ ℤ )
6 5 adantr ( ( 𝜑 ∧ 0 < 𝑁 ) → 𝑀 ∈ ℤ )
7 simpr ( ( 𝜑 ∧ 0 < 𝑁 ) → 0 < 𝑁 )
8 expgt0 ( ( 𝑁 ∈ ℝ ∧ 𝑀 ∈ ℤ ∧ 0 < 𝑁 ) → 0 < ( 𝑁𝑀 ) )
9 4 6 7 8 syl3anc ( ( 𝜑 ∧ 0 < 𝑁 ) → 0 < ( 𝑁𝑀 ) )
10 9 ex ( 𝜑 → ( 0 < 𝑁 → 0 < ( 𝑁𝑀 ) ) )
11 0red ( 𝜑 → 0 ∈ ℝ )
12 11 1 lttrid ( 𝜑 → ( 0 < 𝑁 ↔ ¬ ( 0 = 𝑁𝑁 < 0 ) ) )
13 12 notbid ( 𝜑 → ( ¬ 0 < 𝑁 ↔ ¬ ¬ ( 0 = 𝑁𝑁 < 0 ) ) )
14 notnotr ( ¬ ¬ ( 0 = 𝑁𝑁 < 0 ) → ( 0 = 𝑁𝑁 < 0 ) )
15 0re 0 ∈ ℝ
16 15 ltnri ¬ 0 < 0
17 2 0expd ( 𝜑 → ( 0 ↑ 𝑀 ) = 0 )
18 17 breq2d ( 𝜑 → ( 0 < ( 0 ↑ 𝑀 ) ↔ 0 < 0 ) )
19 16 18 mtbiri ( 𝜑 → ¬ 0 < ( 0 ↑ 𝑀 ) )
20 19 adantr ( ( 𝜑 ∧ 0 = 𝑁 ) → ¬ 0 < ( 0 ↑ 𝑀 ) )
21 simpr ( ( 𝜑 ∧ 0 = 𝑁 ) → 0 = 𝑁 )
22 21 eqcomd ( ( 𝜑 ∧ 0 = 𝑁 ) → 𝑁 = 0 )
23 22 oveq1d ( ( 𝜑 ∧ 0 = 𝑁 ) → ( 𝑁𝑀 ) = ( 0 ↑ 𝑀 ) )
24 23 breq2d ( ( 𝜑 ∧ 0 = 𝑁 ) → ( 0 < ( 𝑁𝑀 ) ↔ 0 < ( 0 ↑ 𝑀 ) ) )
25 20 24 mtbird ( ( 𝜑 ∧ 0 = 𝑁 ) → ¬ 0 < ( 𝑁𝑀 ) )
26 25 ex ( 𝜑 → ( 0 = 𝑁 → ¬ 0 < ( 𝑁𝑀 ) ) )
27 1 renegcld ( 𝜑 → - 𝑁 ∈ ℝ )
28 27 adantr ( ( 𝜑 ∧ 0 < - 𝑁 ) → - 𝑁 ∈ ℝ )
29 5 adantr ( ( 𝜑 ∧ 0 < - 𝑁 ) → 𝑀 ∈ ℤ )
30 simpr ( ( 𝜑 ∧ 0 < - 𝑁 ) → 0 < - 𝑁 )
31 expgt0 ( ( - 𝑁 ∈ ℝ ∧ 𝑀 ∈ ℤ ∧ 0 < - 𝑁 ) → 0 < ( - 𝑁𝑀 ) )
32 28 29 30 31 syl3anc ( ( 𝜑 ∧ 0 < - 𝑁 ) → 0 < ( - 𝑁𝑀 ) )
33 32 ex ( 𝜑 → ( 0 < - 𝑁 → 0 < ( - 𝑁𝑀 ) ) )
34 1 recnd ( 𝜑𝑁 ∈ ℂ )
35 simpr ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( 𝑀 / 2 ) ∈ ℤ )
36 zq ( ( 𝑀 / 2 ) ∈ ℤ → ( 𝑀 / 2 ) ∈ ℚ )
37 36 adantl ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( 𝑀 / 2 ) ∈ ℚ )
38 qden1elz ( ( 𝑀 / 2 ) ∈ ℚ → ( ( denom ‘ ( 𝑀 / 2 ) ) = 1 ↔ ( 𝑀 / 2 ) ∈ ℤ ) )
39 37 38 syl ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( ( denom ‘ ( 𝑀 / 2 ) ) = 1 ↔ ( 𝑀 / 2 ) ∈ ℤ ) )
40 35 39 mpbird ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( denom ‘ ( 𝑀 / 2 ) ) = 1 )
41 40 oveq2d ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( ( 𝑀 / 2 ) · ( denom ‘ ( 𝑀 / 2 ) ) ) = ( ( 𝑀 / 2 ) · 1 ) )
42 qmuldeneqnum ( ( 𝑀 / 2 ) ∈ ℚ → ( ( 𝑀 / 2 ) · ( denom ‘ ( 𝑀 / 2 ) ) ) = ( numer ‘ ( 𝑀 / 2 ) ) )
43 37 42 syl ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( ( 𝑀 / 2 ) · ( denom ‘ ( 𝑀 / 2 ) ) ) = ( numer ‘ ( 𝑀 / 2 ) ) )
44 35 zcnd ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( 𝑀 / 2 ) ∈ ℂ )
45 44 mulid1d ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( ( 𝑀 / 2 ) · 1 ) = ( 𝑀 / 2 ) )
46 41 43 45 3eqtr3rd ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( 𝑀 / 2 ) = ( numer ‘ ( 𝑀 / 2 ) ) )
47 2 nnred ( 𝜑𝑀 ∈ ℝ )
48 2re 2 ∈ ℝ
49 48 a1i ( 𝜑 → 2 ∈ ℝ )
50 2 nngt0d ( 𝜑 → 0 < 𝑀 )
51 2pos 0 < 2
52 51 a1i ( 𝜑 → 0 < 2 )
53 47 49 50 52 divgt0d ( 𝜑 → 0 < ( 𝑀 / 2 ) )
54 qgt0numnn ( ( ( 𝑀 / 2 ) ∈ ℚ ∧ 0 < ( 𝑀 / 2 ) ) → ( numer ‘ ( 𝑀 / 2 ) ) ∈ ℕ )
55 36 53 54 syl2anr ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( numer ‘ ( 𝑀 / 2 ) ) ∈ ℕ )
56 46 55 eqeltrd ( ( 𝜑 ∧ ( 𝑀 / 2 ) ∈ ℤ ) → ( 𝑀 / 2 ) ∈ ℕ )
57 3 56 mtand ( 𝜑 → ¬ ( 𝑀 / 2 ) ∈ ℤ )
58 evend2 ( 𝑀 ∈ ℤ → ( 2 ∥ 𝑀 ↔ ( 𝑀 / 2 ) ∈ ℤ ) )
59 5 58 syl ( 𝜑 → ( 2 ∥ 𝑀 ↔ ( 𝑀 / 2 ) ∈ ℤ ) )
60 57 59 mtbird ( 𝜑 → ¬ 2 ∥ 𝑀 )
61 oexpneg ( ( 𝑁 ∈ ℂ ∧ 𝑀 ∈ ℕ ∧ ¬ 2 ∥ 𝑀 ) → ( - 𝑁𝑀 ) = - ( 𝑁𝑀 ) )
62 34 2 60 61 syl3anc ( 𝜑 → ( - 𝑁𝑀 ) = - ( 𝑁𝑀 ) )
63 62 breq2d ( 𝜑 → ( 0 < ( - 𝑁𝑀 ) ↔ 0 < - ( 𝑁𝑀 ) ) )
64 63 biimpd ( 𝜑 → ( 0 < ( - 𝑁𝑀 ) → 0 < - ( 𝑁𝑀 ) ) )
65 2 nnnn0d ( 𝜑𝑀 ∈ ℕ0 )
66 1 65 reexpcld ( 𝜑 → ( 𝑁𝑀 ) ∈ ℝ )
67 66 renegcld ( 𝜑 → - ( 𝑁𝑀 ) ∈ ℝ )
68 11 67 lttrid ( 𝜑 → ( 0 < - ( 𝑁𝑀 ) ↔ ¬ ( 0 = - ( 𝑁𝑀 ) ∨ - ( 𝑁𝑀 ) < 0 ) ) )
69 pm2.46 ( ¬ ( 0 = - ( 𝑁𝑀 ) ∨ - ( 𝑁𝑀 ) < 0 ) → ¬ - ( 𝑁𝑀 ) < 0 )
70 68 69 syl6bi ( 𝜑 → ( 0 < - ( 𝑁𝑀 ) → ¬ - ( 𝑁𝑀 ) < 0 ) )
71 33 64 70 3syld ( 𝜑 → ( 0 < - 𝑁 → ¬ - ( 𝑁𝑀 ) < 0 ) )
72 1 lt0neg1d ( 𝜑 → ( 𝑁 < 0 ↔ 0 < - 𝑁 ) )
73 66 lt0neg2d ( 𝜑 → ( 0 < ( 𝑁𝑀 ) ↔ - ( 𝑁𝑀 ) < 0 ) )
74 73 notbid ( 𝜑 → ( ¬ 0 < ( 𝑁𝑀 ) ↔ ¬ - ( 𝑁𝑀 ) < 0 ) )
75 71 72 74 3imtr4d ( 𝜑 → ( 𝑁 < 0 → ¬ 0 < ( 𝑁𝑀 ) ) )
76 26 75 jaod ( 𝜑 → ( ( 0 = 𝑁𝑁 < 0 ) → ¬ 0 < ( 𝑁𝑀 ) ) )
77 14 76 syl5 ( 𝜑 → ( ¬ ¬ ( 0 = 𝑁𝑁 < 0 ) → ¬ 0 < ( 𝑁𝑀 ) ) )
78 13 77 sylbid ( 𝜑 → ( ¬ 0 < 𝑁 → ¬ 0 < ( 𝑁𝑀 ) ) )
79 10 78 impcon4bid ( 𝜑 → ( 0 < 𝑁 ↔ 0 < ( 𝑁𝑀 ) ) )