Description: The function F is closed in integers with absolute value less than 1 (namely { -u 1 , 0 , 1 } , see zabsle1 ). (Contributed by Mario Carneiro, 4-Feb-2015)
Ref | Expression | ||
---|---|---|---|
Hypotheses | lgsval.1 | |
|
lgsfcl2.z | |
||
Assertion | lgsfcl2 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | lgsval.1 | |
|
2 | lgsfcl2.z | |
|
3 | 0z | |
|
4 | 0le1 | |
|
5 | fveq2 | |
|
6 | abs0 | |
|
7 | 5 6 | eqtrdi | |
8 | 7 | breq1d | |
9 | 8 2 | elrab2 | |
10 | 3 4 9 | mpbir2an | |
11 | 1z | |
|
12 | 1le1 | |
|
13 | fveq2 | |
|
14 | abs1 | |
|
15 | 13 14 | eqtrdi | |
16 | 15 | breq1d | |
17 | 16 2 | elrab2 | |
18 | 11 12 17 | mpbir2an | |
19 | neg1z | |
|
20 | fveq2 | |
|
21 | ax-1cn | |
|
22 | 21 | absnegi | |
23 | 22 14 | eqtri | |
24 | 20 23 | eqtrdi | |
25 | 24 | breq1d | |
26 | 25 2 | elrab2 | |
27 | 19 12 26 | mpbir2an | |
28 | 18 27 | ifcli | |
29 | 10 28 | ifcli | |
30 | 29 | a1i | |
31 | simpl1 | |
|
32 | 31 | ad2antrr | |
33 | simplr | |
|
34 | simpr | |
|
35 | 34 | neqned | |
36 | eldifsn | |
|
37 | 33 35 36 | sylanbrc | |
38 | 2 | lgslem4 | |
39 | 32 37 38 | syl2anc | |
40 | 30 39 | ifclda | |
41 | simpr | |
|
42 | simpll2 | |
|
43 | simpll3 | |
|
44 | pczcl | |
|
45 | 41 42 43 44 | syl12anc | |
46 | 2 | ssrab3 | |
47 | zsscn | |
|
48 | 46 47 | sstri | |
49 | 2 | lgslem3 | |
50 | 48 49 18 | expcllem | |
51 | 40 45 50 | syl2anc | |
52 | 18 | a1i | |
53 | 51 52 | ifclda | |
54 | 53 1 | fmptd | |