Metamath Proof Explorer


Theorem ocorth

Description: Members of a subset and its complement are orthogonal. (Contributed by NM, 9-Aug-2000) (New usage is discouraged.)

Ref Expression
Assertion ocorth H A H B H A ih B = 0

Proof

Step Hyp Ref Expression
1 ocel H B H B x H B ih x = 0
2 1 simplbda H B H x H B ih x = 0
3 2 adantl H A H H B H x H B ih x = 0
4 oveq2 x = A B ih x = B ih A
5 4 eqeq1d x = A B ih x = 0 B ih A = 0
6 5 rspcv A H x H B ih x = 0 B ih A = 0
7 6 ad2antlr H A H H B H x H B ih x = 0 B ih A = 0
8 ssel2 H A H A
9 ocss H H
10 9 sselda H B H B
11 orthcom A B A ih B = 0 B ih A = 0
12 8 10 11 syl2an H A H H B H A ih B = 0 B ih A = 0
13 7 12 sylibrd H A H H B H x H B ih x = 0 A ih B = 0
14 3 13 mpd H A H H B H A ih B = 0
15 14 anandis H A H B H A ih B = 0
16 15 ex H A H B H A ih B = 0