Metamath Proof Explorer


Theorem mdsymlem8

Description: Lemma for mdsymi . Lemma 4(ii) of Maeda p. 168. (Contributed by NM, 3-Jul-2004) (New usage is discouraged.)

Ref Expression
Hypotheses mdsymlem1.1 A C
mdsymlem1.2 B C
mdsymlem1.3 C = A p
Assertion mdsymlem8 A 0 B 0 B 𝑀 * A A 𝑀 * B

Proof

Step Hyp Ref Expression
1 mdsymlem1.1 A C
2 mdsymlem1.2 B C
3 mdsymlem1.3 C = A p
4 1 2 chjcomi A B = B A
5 4 sseq2i p A B p B A
6 atelch q HAtoms q C
7 atelch r HAtoms r C
8 chjcom q C r C q r = r q
9 6 7 8 syl2an q HAtoms r HAtoms q r = r q
10 9 sseq2d q HAtoms r HAtoms p q r p r q
11 ancom q A r B r B q A
12 11 a1i q HAtoms r HAtoms q A r B r B q A
13 10 12 anbi12d q HAtoms r HAtoms p q r q A r B p r q r B q A
14 13 2rexbiia q HAtoms r HAtoms p q r q A r B q HAtoms r HAtoms p r q r B q A
15 rexcom q HAtoms r HAtoms p r q r B q A r HAtoms q HAtoms p r q r B q A
16 14 15 bitri q HAtoms r HAtoms p q r q A r B r HAtoms q HAtoms p r q r B q A
17 5 16 imbi12i p A B q HAtoms r HAtoms p q r q A r B p B A r HAtoms q HAtoms p r q r B q A
18 17 ralbii p HAtoms p A B q HAtoms r HAtoms p q r q A r B p HAtoms p B A r HAtoms q HAtoms p r q r B q A
19 18 a1i A 0 B 0 p HAtoms p A B q HAtoms r HAtoms p q r q A r B p HAtoms p B A r HAtoms q HAtoms p r q r B q A
20 1 2 3 mdsymlem7 A 0 B 0 B 𝑀 * A p HAtoms p A B q HAtoms r HAtoms p q r q A r B
21 eqid B p = B p
22 2 1 21 mdsymlem7 B 0 A 0 A 𝑀 * B p HAtoms p B A r HAtoms q HAtoms p r q r B q A
23 22 ancoms A 0 B 0 A 𝑀 * B p HAtoms p B A r HAtoms q HAtoms p r q r B q A
24 19 20 23 3bitr4d A 0 B 0 B 𝑀 * A A 𝑀 * B