Metamath Proof Explorer


Theorem chnle

Description: Equivalent expressions for "not less than" in the Hilbert lattice. (Contributed by NM, 9-Jun-2004) (New usage is discouraged.)

Ref Expression
Assertion chnle ACBC¬BAAAB

Proof

Step Hyp Ref Expression
1 sseq2 A=ifACA0BABifACA0
2 1 notbid A=ifACA0¬BA¬BifACA0
3 id A=ifACA0A=ifACA0
4 oveq1 A=ifACA0AB=ifACA0B
5 3 4 psseq12d A=ifACA0AABifACA0ifACA0B
6 2 5 bibi12d A=ifACA0¬BAAAB¬BifACA0ifACA0ifACA0B
7 sseq1 B=ifBCB0BifACA0ifBCB0ifACA0
8 7 notbid B=ifBCB0¬BifACA0¬ifBCB0ifACA0
9 oveq2 B=ifBCB0ifACA0B=ifACA0ifBCB0
10 9 psseq2d B=ifBCB0ifACA0ifACA0BifACA0ifACA0ifBCB0
11 8 10 bibi12d B=ifBCB0¬BifACA0ifACA0ifACA0B¬ifBCB0ifACA0ifACA0ifACA0ifBCB0
12 h0elch 0C
13 12 elimel ifACA0C
14 12 elimel ifBCB0C
15 13 14 chnlei ¬ifBCB0ifACA0ifACA0ifACA0ifBCB0
16 6 11 15 dedth2h ACBC¬BAAAB