Database
BASIC REAL AND COMPLEX FUNCTIONS
Polynomials
Liouville's approximation theorem
aaliou3lem8
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aaliou3lem4
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Unicode
Theorem
aaliou3lem8
Description:
Lemma for
aaliou3
.
(Contributed by
Stefan O'Rear
, 20-Nov-2014)
Ref
Expression
Assertion
aaliou3lem8
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
→
∃
x
∈
ℕ
2
2
−
x
+
1
!
≤
B
2
x
!
A
Proof
Step
Hyp
Ref
Expression
1
2rp
⊢
2
∈
ℝ
+
2
rpdivcl
⊢
2
∈
ℝ
+
∧
B
∈
ℝ
+
→
2
B
∈
ℝ
+
3
1
2
mpan
⊢
B
∈
ℝ
+
→
2
B
∈
ℝ
+
4
3
rpred
⊢
B
∈
ℝ
+
→
2
B
∈
ℝ
5
2re
⊢
2
∈
ℝ
6
1lt2
⊢
1
<
2
7
expnbnd
⊢
2
B
∈
ℝ
∧
2
∈
ℝ
∧
1
<
2
→
∃
a
∈
ℕ
2
B
<
2
a
8
5
6
7
mp3an23
⊢
2
B
∈
ℝ
→
∃
a
∈
ℕ
2
B
<
2
a
9
4
8
syl
⊢
B
∈
ℝ
+
→
∃
a
∈
ℕ
2
B
<
2
a
10
9
adantl
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
→
∃
a
∈
ℕ
2
B
<
2
a
11
simprl
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
∈
ℕ
12
simpll
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
A
∈
ℕ
13
nnaddm1cl
⊢
a
∈
ℕ
∧
A
∈
ℕ
→
a
+
A
-
1
∈
ℕ
14
11
12
13
syl2anc
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
∈
ℕ
15
simplr
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
B
∈
ℝ
+
16
rerpdivcl
⊢
2
∈
ℝ
∧
B
∈
ℝ
+
→
2
B
∈
ℝ
17
5
15
16
sylancr
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
B
∈
ℝ
18
11
nnnn0d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
∈
ℕ
0
19
reexpcl
⊢
2
∈
ℝ
∧
a
∈
ℕ
0
→
2
a
∈
ℝ
20
5
18
19
sylancr
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
∈
ℝ
21
11
12
nnaddcld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
∈
ℕ
22
nnm1nn0
⊢
a
+
A
∈
ℕ
→
a
+
A
-
1
∈
ℕ
0
23
21
22
syl
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
∈
ℕ
0
24
peano2nn0
⊢
a
+
A
-
1
∈
ℕ
0
→
a
+
A
-
1
+
1
∈
ℕ
0
25
23
24
syl
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
∈
ℕ
0
26
25
faccld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
!
∈
ℕ
27
26
nnzd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
!
∈
ℤ
28
23
faccld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
!
∈
ℕ
29
28
nnzd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
!
∈
ℤ
30
12
nnzd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
A
∈
ℤ
31
29
30
zmulcld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
!
A
∈
ℤ
32
27
31
zsubcld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
∈
ℤ
33
rpexpcl
⊢
2
∈
ℝ
+
∧
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
∈
ℤ
→
2
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
∈
ℝ
+
34
1
32
33
sylancr
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
∈
ℝ
+
35
34
rpred
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
∈
ℝ
36
simprr
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
B
<
2
a
37
17
20
36
ltled
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
B
≤
2
a
38
5
a1i
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
∈
ℝ
39
1le2
⊢
1
≤
2
40
39
a1i
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
1
≤
2
41
11
nnred
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
∈
ℝ
42
28
nnred
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
!
∈
ℝ
43
18
nn0ge0d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
0
≤
a
44
28
nnge1d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
1
≤
a
+
A
-
1
!
45
41
42
43
44
lemulge12d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
≤
a
+
A
-
1
!
a
46
facp1
⊢
a
+
A
-
1
∈
ℕ
0
→
a
+
A
-
1
+
1
!
=
a
+
A
-
1
!
a
+
A
-
1
+
1
47
23
46
syl
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
!
=
a
+
A
-
1
!
a
+
A
-
1
+
1
48
47
oveq1d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
=
a
+
A
-
1
!
a
+
A
-
1
+
1
−
a
+
A
-
1
!
A
49
28
nncnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
!
∈
ℂ
50
25
nn0cnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
∈
ℂ
51
12
nncnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
A
∈
ℂ
52
49
50
51
subdid
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
!
a
+
A
-
1
+
1
-
A
=
a
+
A
-
1
!
a
+
A
-
1
+
1
−
a
+
A
-
1
!
A
53
11
nncnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
∈
ℂ
54
21
nncnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
∈
ℂ
55
1cnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
1
∈
ℂ
56
54
55
npcand
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
=
a
+
A
57
53
51
56
mvrraddd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
-
A
=
a
58
57
oveq2d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
!
a
+
A
-
1
+
1
-
A
=
a
+
A
-
1
!
a
59
48
52
58
3eqtr2d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
=
a
+
A
-
1
!
a
60
45
59
breqtrrd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
≤
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
61
11
nnzd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
∈
ℤ
62
eluz
⊢
a
∈
ℤ
∧
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
∈
ℤ
→
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
∈
ℤ
≥
a
↔
a
≤
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
63
61
32
62
syl2anc
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
∈
ℤ
≥
a
↔
a
≤
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
64
60
63
mpbird
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
∈
ℤ
≥
a
65
38
40
64
leexp2ad
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
≤
2
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
66
17
20
35
37
65
letrd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
B
≤
2
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
67
rpcnne0
⊢
2
∈
ℝ
+
→
2
∈
ℂ
∧
2
≠
0
68
1
67
mp1i
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
∈
ℂ
∧
2
≠
0
69
expsub
⊢
2
∈
ℂ
∧
2
≠
0
∧
a
+
A
-
1
+
1
!
∈
ℤ
∧
a
+
A
-
1
!
A
∈
ℤ
→
2
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
=
2
a
+
A
-
1
+
1
!
2
a
+
A
-
1
!
A
70
68
27
31
69
syl12anc
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
=
2
a
+
A
-
1
+
1
!
2
a
+
A
-
1
!
A
71
2cn
⊢
2
∈
ℂ
72
71
a1i
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
∈
ℂ
73
12
nnnn0d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
A
∈
ℕ
0
74
28
nnnn0d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
!
∈
ℕ
0
75
72
73
74
expmuld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
!
A
=
2
a
+
A
-
1
!
A
76
75
oveq2d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
2
a
+
A
-
1
!
A
=
2
a
+
A
-
1
+
1
!
2
a
+
A
-
1
!
A
77
rpexpcl
⊢
2
∈
ℝ
+
∧
a
+
A
-
1
+
1
!
∈
ℤ
→
2
a
+
A
-
1
+
1
!
∈
ℝ
+
78
1
27
77
sylancr
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
∈
ℝ
+
79
78
rpcnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
∈
ℂ
80
rpexpcl
⊢
2
∈
ℝ
+
∧
a
+
A
-
1
!
∈
ℤ
→
2
a
+
A
-
1
!
∈
ℝ
+
81
1
29
80
sylancr
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
!
∈
ℝ
+
82
81
30
rpexpcld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
!
A
∈
ℝ
+
83
82
rpcnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
!
A
∈
ℂ
84
82
rpne0d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
!
A
≠
0
85
79
83
84
divrecd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
2
a
+
A
-
1
!
A
=
2
a
+
A
-
1
+
1
!
1
2
a
+
A
-
1
!
A
86
70
76
85
3eqtrrd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
1
2
a
+
A
-
1
!
A
=
2
a
+
A
-
1
+
1
!
−
a
+
A
-
1
!
A
87
66
86
breqtrrd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
B
≤
2
a
+
A
-
1
+
1
!
1
2
a
+
A
-
1
!
A
88
82
rpreccld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
1
2
a
+
A
-
1
!
A
∈
ℝ
+
89
78
88
rpmulcld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
1
2
a
+
A
-
1
!
A
∈
ℝ
+
90
89
rpred
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
1
2
a
+
A
-
1
!
A
∈
ℝ
91
38
90
15
ledivmuld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
B
≤
2
a
+
A
-
1
+
1
!
1
2
a
+
A
-
1
!
A
↔
2
≤
B
2
a
+
A
-
1
+
1
!
1
2
a
+
A
-
1
!
A
92
87
91
mpbid
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
≤
B
2
a
+
A
-
1
+
1
!
1
2
a
+
A
-
1
!
A
93
15
rpcnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
B
∈
ℂ
94
88
rpcnd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
1
2
a
+
A
-
1
!
A
∈
ℂ
95
93
79
94
mul12d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
B
2
a
+
A
-
1
+
1
!
1
2
a
+
A
-
1
!
A
=
2
a
+
A
-
1
+
1
!
B
1
2
a
+
A
-
1
!
A
96
92
95
breqtrd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
≤
2
a
+
A
-
1
+
1
!
B
1
2
a
+
A
-
1
!
A
97
15
88
rpmulcld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
B
1
2
a
+
A
-
1
!
A
∈
ℝ
+
98
97
rpred
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
B
1
2
a
+
A
-
1
!
A
∈
ℝ
99
38
98
78
ledivmuld
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
2
a
+
A
-
1
+
1
!
≤
B
1
2
a
+
A
-
1
!
A
↔
2
≤
2
a
+
A
-
1
+
1
!
B
1
2
a
+
A
-
1
!
A
100
96
99
mpbird
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
2
a
+
A
-
1
+
1
!
≤
B
1
2
a
+
A
-
1
!
A
101
26
nnnn0d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
a
+
A
-
1
+
1
!
∈
ℕ
0
102
expneg
⊢
2
∈
ℂ
∧
a
+
A
-
1
+
1
!
∈
ℕ
0
→
2
−
a
+
A
-
1
+
1
!
=
1
2
a
+
A
-
1
+
1
!
103
71
101
102
sylancr
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
−
a
+
A
-
1
+
1
!
=
1
2
a
+
A
-
1
+
1
!
104
103
oveq2d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
2
−
a
+
A
-
1
+
1
!
=
2
1
2
a
+
A
-
1
+
1
!
105
78
rpne0d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
a
+
A
-
1
+
1
!
≠
0
106
72
79
105
divrecd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
2
a
+
A
-
1
+
1
!
=
2
1
2
a
+
A
-
1
+
1
!
107
104
106
eqtr4d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
2
−
a
+
A
-
1
+
1
!
=
2
2
a
+
A
-
1
+
1
!
108
93
83
84
divrecd
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
B
2
a
+
A
-
1
!
A
=
B
1
2
a
+
A
-
1
!
A
109
100
107
108
3brtr4d
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
2
2
−
a
+
A
-
1
+
1
!
≤
B
2
a
+
A
-
1
!
A
110
fvoveq1
⊢
x
=
a
+
A
-
1
→
x
+
1
!
=
a
+
A
-
1
+
1
!
111
110
negeqd
⊢
x
=
a
+
A
-
1
→
−
x
+
1
!
=
−
a
+
A
-
1
+
1
!
112
111
oveq2d
⊢
x
=
a
+
A
-
1
→
2
−
x
+
1
!
=
2
−
a
+
A
-
1
+
1
!
113
112
oveq2d
⊢
x
=
a
+
A
-
1
→
2
2
−
x
+
1
!
=
2
2
−
a
+
A
-
1
+
1
!
114
fveq2
⊢
x
=
a
+
A
-
1
→
x
!
=
a
+
A
-
1
!
115
114
oveq2d
⊢
x
=
a
+
A
-
1
→
2
x
!
=
2
a
+
A
-
1
!
116
115
oveq1d
⊢
x
=
a
+
A
-
1
→
2
x
!
A
=
2
a
+
A
-
1
!
A
117
116
oveq2d
⊢
x
=
a
+
A
-
1
→
B
2
x
!
A
=
B
2
a
+
A
-
1
!
A
118
113
117
breq12d
⊢
x
=
a
+
A
-
1
→
2
2
−
x
+
1
!
≤
B
2
x
!
A
↔
2
2
−
a
+
A
-
1
+
1
!
≤
B
2
a
+
A
-
1
!
A
119
118
rspcev
⊢
a
+
A
-
1
∈
ℕ
∧
2
2
−
a
+
A
-
1
+
1
!
≤
B
2
a
+
A
-
1
!
A
→
∃
x
∈
ℕ
2
2
−
x
+
1
!
≤
B
2
x
!
A
120
14
109
119
syl2anc
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
∧
a
∈
ℕ
∧
2
B
<
2
a
→
∃
x
∈
ℕ
2
2
−
x
+
1
!
≤
B
2
x
!
A
121
10
120
rexlimddv
⊢
A
∈
ℕ
∧
B
∈
ℝ
+
→
∃
x
∈
ℕ
2
2
−
x
+
1
!
≤
B
2
x
!
A