Description: R has no multiplicative (right) identity. (Contributed by AV, 12-Feb-2020)
Ref | Expression | ||
---|---|---|---|
Hypotheses | 2zrng.e | |
|
2zrngbas.r | |
||
2zrngmmgm.1 | |
||
Assertion | 2zrngnmrid | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 2zrng.e | |
|
2 | 2zrngbas.r | |
|
3 | 2zrngmmgm.1 | |
|
4 | eldifsn | |
|
5 | eqeq1 | |
|
6 | 5 | rexbidv | |
7 | 6 1 | elrab2 | |
8 | zcn | |
|
9 | 8 | adantr | |
10 | 7 9 | sylbi | |
11 | 10 | anim1i | |
12 | 4 11 | sylbi | |
13 | eqeq1 | |
|
14 | 13 | rexbidv | |
15 | 14 1 | elrab2 | |
16 | zcn | |
|
17 | 16 | adantr | |
18 | 15 17 | sylbi | |
19 | 18 | ancli | |
20 | 1 | 1neven | |
21 | elnelne2 | |
|
22 | 20 21 | mpan2 | |
23 | 22 | ad2antrl | |
24 | simpr | |
|
25 | 24 | anim2i | |
26 | 3anass | |
|
27 | ancom | |
|
28 | 26 27 | bitri | |
29 | 25 28 | sylibr | |
30 | divcan3 | |
|
31 | 29 30 | syl | |
32 | divid | |
|
33 | 32 | adantr | |
34 | 23 31 33 | 3netr4d | |
35 | simpl | |
|
36 | mulcl | |
|
37 | 35 24 36 | syl2an | |
38 | 35 | adantr | |
39 | simpl | |
|
40 | div11 | |
|
41 | 37 38 39 40 | syl3anc | |
42 | 41 | biimprd | |
43 | 42 | necon3d | |
44 | 34 43 | mpd | |
45 | 12 19 44 | syl2an | |
46 | 45 | rgen2 | |