Metamath Proof Explorer


Theorem 2zrngnmrid

Description: R has no multiplicative (right) identity. (Contributed by AV, 12-Feb-2020)

Ref Expression
Hypotheses 2zrng.e E = z | x z = 2 x
2zrngbas.r R = fld 𝑠 E
2zrngmmgm.1 M = mulGrp R
Assertion 2zrngnmrid a E 0 b E a b a

Proof

Step Hyp Ref Expression
1 2zrng.e E = z | x z = 2 x
2 2zrngbas.r R = fld 𝑠 E
3 2zrngmmgm.1 M = mulGrp R
4 eldifsn a E 0 a E a 0
5 eqeq1 z = a z = 2 x a = 2 x
6 5 rexbidv z = a x z = 2 x x a = 2 x
7 6 1 elrab2 a E a x a = 2 x
8 zcn a a
9 8 adantr a x a = 2 x a
10 7 9 sylbi a E a
11 10 anim1i a E a 0 a a 0
12 4 11 sylbi a E 0 a a 0
13 eqeq1 z = b z = 2 x b = 2 x
14 13 rexbidv z = b x z = 2 x x b = 2 x
15 14 1 elrab2 b E b x b = 2 x
16 zcn b b
17 16 adantr b x b = 2 x b
18 15 17 sylbi b E b
19 18 ancli b E b E b
20 1 1neven 1 E
21 elnelne2 b E 1 E b 1
22 20 21 mpan2 b E b 1
23 22 ad2antrl a a 0 b E b b 1
24 simpr b E b b
25 24 anim2i a a 0 b E b a a 0 b
26 3anass b a a 0 b a a 0
27 ancom b a a 0 a a 0 b
28 26 27 bitri b a a 0 a a 0 b
29 25 28 sylibr a a 0 b E b b a a 0
30 divcan3 b a a 0 a b a = b
31 29 30 syl a a 0 b E b a b a = b
32 divid a a 0 a a = 1
33 32 adantr a a 0 b E b a a = 1
34 23 31 33 3netr4d a a 0 b E b a b a a a
35 simpl a a 0 a
36 mulcl a b a b
37 35 24 36 syl2an a a 0 b E b a b
38 35 adantr a a 0 b E b a
39 simpl a a 0 b E b a a 0
40 div11 a b a a a 0 a b a = a a a b = a
41 37 38 39 40 syl3anc a a 0 b E b a b a = a a a b = a
42 41 biimprd a a 0 b E b a b = a a b a = a a
43 42 necon3d a a 0 b E b a b a a a a b a
44 34 43 mpd a a 0 b E b a b a
45 12 19 44 syl2an a E 0 b E a b a
46 45 rgen2 a E 0 b E a b a