Metamath Proof Explorer


Theorem dmdbr2

Description: Binary relation expressing the dual modular pair property. This version has a weaker constraint than dmdbr . (Contributed by NM, 30-Jun-2004) (New usage is discouraged.)

Ref Expression
Assertion dmdbr2 ACBCA𝑀*BxCBxxABxAB

Proof

Step Hyp Ref Expression
1 dmdbr ACBCA𝑀*BxCBxxAB=xAB
2 chincl xCACxAC
3 2 ancoms ACxCxAC
4 3 adantlr ACBCxCxAC
5 simplr ACBCxCBC
6 simpr ACBCxCxC
7 inss1 xAx
8 chlub xACBCxCxAxBxxABx
9 8 biimpd xACBCxCxAxBxxABx
10 7 9 mpani xACBCxCBxxABx
11 4 5 6 10 syl3anc ACBCxCBxxABx
12 simpll ACBCxCAC
13 inss2 xAA
14 chlej1 xACACBCxAAxABAB
15 13 14 mpan2 xACACBCxABAB
16 4 12 5 15 syl3anc ACBCxCxABAB
17 11 16 jctird ACBCxCBxxABxxABAB
18 ssin xABxxABABxABxAB
19 17 18 imbitrdi ACBCxCBxxABxAB
20 eqss xAB=xABxABxABxABxAB
21 20 baib xABxABxAB=xABxABxAB
22 19 21 syl6 ACBCxCBxxAB=xABxABxAB
23 22 pm5.74d ACBCxCBxxAB=xABBxxABxAB
24 23 ralbidva ACBCxCBxxAB=xABxCBxxABxAB
25 1 24 bitrd ACBCA𝑀*BxCBxxABxAB