Metamath Proof Explorer


Theorem pjoml2i

Description: Variation of orthomodular law. Definition in Kalmbach p. 22. (Contributed by NM, 31-Oct-2000) (New usage is discouraged.)

Ref Expression
Hypotheses pjoml2.1 A C
pjoml2.2 B C
Assertion pjoml2i A B A A B = B

Proof

Step Hyp Ref Expression
1 pjoml2.1 A C
2 pjoml2.2 B C
3 inss2 A B B
4 1 choccli A C
5 4 2 chincli A B C
6 1 5 2 chlubii A B A B B A A B B
7 3 6 mpan2 A B A A B B
8 1 5 chdmj1i A A B = A A B
9 8 ineq2i B A A B = B A A B
10 incom B A = A B
11 10 ineq1i B A A B = A B A B
12 inass B A A B = B A A B
13 5 chocini A B A B = 0
14 11 12 13 3eqtr3i B A A B = 0
15 9 14 eqtri B A A B = 0
16 1 5 chjcli A A B C
17 2 chshii B S
18 16 17 pjomli A A B B B A A B = 0 A A B = B
19 7 15 18 sylancl A B A A B = B