Step |
Hyp |
Ref |
Expression |
1 |
|
1re |
⊢ 1 ∈ ℝ |
2 |
|
elicopnf |
⊢ ( 1 ∈ ℝ → ( 𝑋 ∈ ( 1 [,) +∞ ) ↔ ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) ) ) |
3 |
1 2
|
ax-mp |
⊢ ( 𝑋 ∈ ( 1 [,) +∞ ) ↔ ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) ) |
4 |
|
id |
⊢ ( ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) → ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) ) |
5 |
3 4
|
sylbi |
⊢ ( 𝑋 ∈ ( 1 [,) +∞ ) → ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) ) |
6 |
5
|
adantl |
⊢ ( ( 𝐵 ∈ ( 1 (,) +∞ ) ∧ 𝑋 ∈ ( 1 [,) +∞ ) ) → ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) ) |
7 |
|
logge0 |
⊢ ( ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) → 0 ≤ ( log ‘ 𝑋 ) ) |
8 |
6 7
|
syl |
⊢ ( ( 𝐵 ∈ ( 1 (,) +∞ ) ∧ 𝑋 ∈ ( 1 [,) +∞ ) ) → 0 ≤ ( log ‘ 𝑋 ) ) |
9 |
|
simpl |
⊢ ( ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) → 𝑋 ∈ ℝ ) |
10 |
|
0lt1 |
⊢ 0 < 1 |
11 |
|
0red |
⊢ ( 𝑋 ∈ ℝ → 0 ∈ ℝ ) |
12 |
|
1red |
⊢ ( 𝑋 ∈ ℝ → 1 ∈ ℝ ) |
13 |
|
id |
⊢ ( 𝑋 ∈ ℝ → 𝑋 ∈ ℝ ) |
14 |
|
ltletr |
⊢ ( ( 0 ∈ ℝ ∧ 1 ∈ ℝ ∧ 𝑋 ∈ ℝ ) → ( ( 0 < 1 ∧ 1 ≤ 𝑋 ) → 0 < 𝑋 ) ) |
15 |
11 12 13 14
|
syl3anc |
⊢ ( 𝑋 ∈ ℝ → ( ( 0 < 1 ∧ 1 ≤ 𝑋 ) → 0 < 𝑋 ) ) |
16 |
10 15
|
mpani |
⊢ ( 𝑋 ∈ ℝ → ( 1 ≤ 𝑋 → 0 < 𝑋 ) ) |
17 |
16
|
imp |
⊢ ( ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) → 0 < 𝑋 ) |
18 |
9 17
|
elrpd |
⊢ ( ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) → 𝑋 ∈ ℝ+ ) |
19 |
3 18
|
sylbi |
⊢ ( 𝑋 ∈ ( 1 [,) +∞ ) → 𝑋 ∈ ℝ+ ) |
20 |
19
|
relogcld |
⊢ ( 𝑋 ∈ ( 1 [,) +∞ ) → ( log ‘ 𝑋 ) ∈ ℝ ) |
21 |
20
|
adantl |
⊢ ( ( 𝐵 ∈ ( 1 (,) +∞ ) ∧ 𝑋 ∈ ( 1 [,) +∞ ) ) → ( log ‘ 𝑋 ) ∈ ℝ ) |
22 |
|
1xr |
⊢ 1 ∈ ℝ* |
23 |
|
elioopnf |
⊢ ( 1 ∈ ℝ* → ( 𝐵 ∈ ( 1 (,) +∞ ) ↔ ( 𝐵 ∈ ℝ ∧ 1 < 𝐵 ) ) ) |
24 |
22 23
|
ax-mp |
⊢ ( 𝐵 ∈ ( 1 (,) +∞ ) ↔ ( 𝐵 ∈ ℝ ∧ 1 < 𝐵 ) ) |
25 |
|
simpl |
⊢ ( ( 𝐵 ∈ ℝ ∧ 1 < 𝐵 ) → 𝐵 ∈ ℝ ) |
26 |
|
0red |
⊢ ( 𝐵 ∈ ℝ → 0 ∈ ℝ ) |
27 |
|
1red |
⊢ ( 𝐵 ∈ ℝ → 1 ∈ ℝ ) |
28 |
|
id |
⊢ ( 𝐵 ∈ ℝ → 𝐵 ∈ ℝ ) |
29 |
|
lttr |
⊢ ( ( 0 ∈ ℝ ∧ 1 ∈ ℝ ∧ 𝐵 ∈ ℝ ) → ( ( 0 < 1 ∧ 1 < 𝐵 ) → 0 < 𝐵 ) ) |
30 |
26 27 28 29
|
syl3anc |
⊢ ( 𝐵 ∈ ℝ → ( ( 0 < 1 ∧ 1 < 𝐵 ) → 0 < 𝐵 ) ) |
31 |
10 30
|
mpani |
⊢ ( 𝐵 ∈ ℝ → ( 1 < 𝐵 → 0 < 𝐵 ) ) |
32 |
31
|
imp |
⊢ ( ( 𝐵 ∈ ℝ ∧ 1 < 𝐵 ) → 0 < 𝐵 ) |
33 |
25 32
|
elrpd |
⊢ ( ( 𝐵 ∈ ℝ ∧ 1 < 𝐵 ) → 𝐵 ∈ ℝ+ ) |
34 |
24 33
|
sylbi |
⊢ ( 𝐵 ∈ ( 1 (,) +∞ ) → 𝐵 ∈ ℝ+ ) |
35 |
34
|
relogcld |
⊢ ( 𝐵 ∈ ( 1 (,) +∞ ) → ( log ‘ 𝐵 ) ∈ ℝ ) |
36 |
35
|
adantr |
⊢ ( ( 𝐵 ∈ ( 1 (,) +∞ ) ∧ 𝑋 ∈ ( 1 [,) +∞ ) ) → ( log ‘ 𝐵 ) ∈ ℝ ) |
37 |
|
regt1loggt0 |
⊢ ( 𝐵 ∈ ( 1 (,) +∞ ) → 0 < ( log ‘ 𝐵 ) ) |
38 |
37
|
adantr |
⊢ ( ( 𝐵 ∈ ( 1 (,) +∞ ) ∧ 𝑋 ∈ ( 1 [,) +∞ ) ) → 0 < ( log ‘ 𝐵 ) ) |
39 |
|
ge0div |
⊢ ( ( ( log ‘ 𝑋 ) ∈ ℝ ∧ ( log ‘ 𝐵 ) ∈ ℝ ∧ 0 < ( log ‘ 𝐵 ) ) → ( 0 ≤ ( log ‘ 𝑋 ) ↔ 0 ≤ ( ( log ‘ 𝑋 ) / ( log ‘ 𝐵 ) ) ) ) |
40 |
21 36 38 39
|
syl3anc |
⊢ ( ( 𝐵 ∈ ( 1 (,) +∞ ) ∧ 𝑋 ∈ ( 1 [,) +∞ ) ) → ( 0 ≤ ( log ‘ 𝑋 ) ↔ 0 ≤ ( ( log ‘ 𝑋 ) / ( log ‘ 𝐵 ) ) ) ) |
41 |
8 40
|
mpbid |
⊢ ( ( 𝐵 ∈ ( 1 (,) +∞ ) ∧ 𝑋 ∈ ( 1 [,) +∞ ) ) → 0 ≤ ( ( log ‘ 𝑋 ) / ( log ‘ 𝐵 ) ) ) |
42 |
|
recn |
⊢ ( 𝐵 ∈ ℝ → 𝐵 ∈ ℂ ) |
43 |
42
|
adantr |
⊢ ( ( 𝐵 ∈ ℝ ∧ 1 < 𝐵 ) → 𝐵 ∈ ℂ ) |
44 |
32
|
gt0ne0d |
⊢ ( ( 𝐵 ∈ ℝ ∧ 1 < 𝐵 ) → 𝐵 ≠ 0 ) |
45 |
27 28
|
ltlend |
⊢ ( 𝐵 ∈ ℝ → ( 1 < 𝐵 ↔ ( 1 ≤ 𝐵 ∧ 𝐵 ≠ 1 ) ) ) |
46 |
45
|
simplbda |
⊢ ( ( 𝐵 ∈ ℝ ∧ 1 < 𝐵 ) → 𝐵 ≠ 1 ) |
47 |
43 44 46
|
3jca |
⊢ ( ( 𝐵 ∈ ℝ ∧ 1 < 𝐵 ) → ( 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ∧ 𝐵 ≠ 1 ) ) |
48 |
|
eldifpr |
⊢ ( 𝐵 ∈ ( ℂ ∖ { 0 , 1 } ) ↔ ( 𝐵 ∈ ℂ ∧ 𝐵 ≠ 0 ∧ 𝐵 ≠ 1 ) ) |
49 |
47 24 48
|
3imtr4i |
⊢ ( 𝐵 ∈ ( 1 (,) +∞ ) → 𝐵 ∈ ( ℂ ∖ { 0 , 1 } ) ) |
50 |
|
recn |
⊢ ( 𝑋 ∈ ℝ → 𝑋 ∈ ℂ ) |
51 |
50
|
adantr |
⊢ ( ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) → 𝑋 ∈ ℂ ) |
52 |
17
|
gt0ne0d |
⊢ ( ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) → 𝑋 ≠ 0 ) |
53 |
51 52
|
jca |
⊢ ( ( 𝑋 ∈ ℝ ∧ 1 ≤ 𝑋 ) → ( 𝑋 ∈ ℂ ∧ 𝑋 ≠ 0 ) ) |
54 |
|
eldifsn |
⊢ ( 𝑋 ∈ ( ℂ ∖ { 0 } ) ↔ ( 𝑋 ∈ ℂ ∧ 𝑋 ≠ 0 ) ) |
55 |
53 3 54
|
3imtr4i |
⊢ ( 𝑋 ∈ ( 1 [,) +∞ ) → 𝑋 ∈ ( ℂ ∖ { 0 } ) ) |
56 |
|
logbval |
⊢ ( ( 𝐵 ∈ ( ℂ ∖ { 0 , 1 } ) ∧ 𝑋 ∈ ( ℂ ∖ { 0 } ) ) → ( 𝐵 logb 𝑋 ) = ( ( log ‘ 𝑋 ) / ( log ‘ 𝐵 ) ) ) |
57 |
49 55 56
|
syl2an |
⊢ ( ( 𝐵 ∈ ( 1 (,) +∞ ) ∧ 𝑋 ∈ ( 1 [,) +∞ ) ) → ( 𝐵 logb 𝑋 ) = ( ( log ‘ 𝑋 ) / ( log ‘ 𝐵 ) ) ) |
58 |
41 57
|
breqtrrd |
⊢ ( ( 𝐵 ∈ ( 1 (,) +∞ ) ∧ 𝑋 ∈ ( 1 [,) +∞ ) ) → 0 ≤ ( 𝐵 logb 𝑋 ) ) |