Step |
Hyp |
Ref |
Expression |
1 |
|
eluzelre |
⊢ ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) → 𝐵 ∈ ℝ ) |
2 |
1
|
adantr |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ) → 𝐵 ∈ ℝ ) |
3 |
|
eluz2nn |
⊢ ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) → 𝐵 ∈ ℕ ) |
4 |
3
|
nnne0d |
⊢ ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) → 𝐵 ≠ 0 ) |
5 |
4
|
adantr |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ) → 𝐵 ≠ 0 ) |
6 |
|
simpr |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ) → 𝑁 ∈ ℤ ) |
7 |
2 5 6
|
3jca |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ) → ( 𝐵 ∈ ℝ ∧ 𝐵 ≠ 0 ∧ 𝑁 ∈ ℤ ) ) |
8 |
7
|
3adant3 |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → ( 𝐵 ∈ ℝ ∧ 𝐵 ≠ 0 ∧ 𝑁 ∈ ℤ ) ) |
9 |
|
reexpclz |
⊢ ( ( 𝐵 ∈ ℝ ∧ 𝐵 ≠ 0 ∧ 𝑁 ∈ ℤ ) → ( 𝐵 ↑ 𝑁 ) ∈ ℝ ) |
10 |
8 9
|
syl |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → ( 𝐵 ↑ 𝑁 ) ∈ ℝ ) |
11 |
|
0red |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 0 ∈ ℝ ) |
12 |
1
|
3ad2ant1 |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 𝐵 ∈ ℝ ) |
13 |
4
|
3ad2ant1 |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 𝐵 ≠ 0 ) |
14 |
|
simp2 |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 𝑁 ∈ ℤ ) |
15 |
12 13 14
|
reexpclzd |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → ( 𝐵 ↑ 𝑁 ) ∈ ℝ ) |
16 |
3
|
nngt0d |
⊢ ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) → 0 < 𝐵 ) |
17 |
16
|
3ad2ant1 |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 0 < 𝐵 ) |
18 |
|
expgt0 |
⊢ ( ( 𝐵 ∈ ℝ ∧ 𝑁 ∈ ℤ ∧ 0 < 𝐵 ) → 0 < ( 𝐵 ↑ 𝑁 ) ) |
19 |
12 14 17 18
|
syl3anc |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 0 < ( 𝐵 ↑ 𝑁 ) ) |
20 |
11 15 19
|
ltled |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 0 ≤ ( 𝐵 ↑ 𝑁 ) ) |
21 |
|
0zd |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 0 ∈ ℤ ) |
22 |
|
eluz2gt1 |
⊢ ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) → 1 < 𝐵 ) |
23 |
22
|
3ad2ant1 |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 1 < 𝐵 ) |
24 |
|
simp3 |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 𝑁 < 0 ) |
25 |
|
ltexp2a |
⊢ ( ( ( 𝐵 ∈ ℝ ∧ 𝑁 ∈ ℤ ∧ 0 ∈ ℤ ) ∧ ( 1 < 𝐵 ∧ 𝑁 < 0 ) ) → ( 𝐵 ↑ 𝑁 ) < ( 𝐵 ↑ 0 ) ) |
26 |
12 14 21 23 24 25
|
syl32anc |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → ( 𝐵 ↑ 𝑁 ) < ( 𝐵 ↑ 0 ) ) |
27 |
|
eluzelcn |
⊢ ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) → 𝐵 ∈ ℂ ) |
28 |
27
|
exp0d |
⊢ ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) → ( 𝐵 ↑ 0 ) = 1 ) |
29 |
28
|
eqcomd |
⊢ ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) → 1 = ( 𝐵 ↑ 0 ) ) |
30 |
29
|
3ad2ant1 |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → 1 = ( 𝐵 ↑ 0 ) ) |
31 |
26 30
|
breqtrrd |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → ( 𝐵 ↑ 𝑁 ) < 1 ) |
32 |
|
0re |
⊢ 0 ∈ ℝ |
33 |
|
1xr |
⊢ 1 ∈ ℝ* |
34 |
32 33
|
pm3.2i |
⊢ ( 0 ∈ ℝ ∧ 1 ∈ ℝ* ) |
35 |
|
elico2 |
⊢ ( ( 0 ∈ ℝ ∧ 1 ∈ ℝ* ) → ( ( 𝐵 ↑ 𝑁 ) ∈ ( 0 [,) 1 ) ↔ ( ( 𝐵 ↑ 𝑁 ) ∈ ℝ ∧ 0 ≤ ( 𝐵 ↑ 𝑁 ) ∧ ( 𝐵 ↑ 𝑁 ) < 1 ) ) ) |
36 |
34 35
|
mp1i |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → ( ( 𝐵 ↑ 𝑁 ) ∈ ( 0 [,) 1 ) ↔ ( ( 𝐵 ↑ 𝑁 ) ∈ ℝ ∧ 0 ≤ ( 𝐵 ↑ 𝑁 ) ∧ ( 𝐵 ↑ 𝑁 ) < 1 ) ) ) |
37 |
10 20 31 36
|
mpbir3and |
⊢ ( ( 𝐵 ∈ ( ℤ≥ ‘ 2 ) ∧ 𝑁 ∈ ℤ ∧ 𝑁 < 0 ) → ( 𝐵 ↑ 𝑁 ) ∈ ( 0 [,) 1 ) ) |