Metamath Proof Explorer


Theorem chdmm1i

Description: De Morgan's law for meet in a Hilbert lattice. (Contributed by NM, 21-Jun-2004) (New usage is discouraged.)

Ref Expression
Hypotheses ch0le.1 AC
chjcl.2 BC
Assertion chdmm1i AB=AB

Proof

Step Hyp Ref Expression
1 ch0le.1 AC
2 chjcl.2 BC
3 1 choccli AC
4 2 choccli BC
5 3 4 chub1i AAB
6 3 4 chjcli ABC
7 1 6 chsscon1i AABABA
8 5 7 mpbi ABA
9 4 3 chub2i BAB
10 2 6 chsscon1i BABABB
11 9 10 mpbi ABB
12 8 11 ssini ABAB
13 1 2 chincli ABC
14 6 13 chsscon1i ABABABAB
15 12 14 mpbi ABAB
16 inss1 ABA
17 13 1 chsscon3i ABAAAB
18 16 17 mpbi AAB
19 inss2 ABB
20 13 2 chsscon3i ABBBAB
21 19 20 mpbi BAB
22 13 choccli ABC
23 3 4 22 chlubii AABBABABAB
24 18 21 23 mp2an ABAB
25 15 24 eqssi AB=AB