Metamath Proof Explorer


Theorem sshjval3

Description: Value of join for subsets of Hilbert space in terms of supremum: the join is the supremum of its two arguments. Based on the definition of join in Beran p. 3. For later convenience we prove a general version that works for any subset of Hilbert space, not just the elements of the lattice CH . (Contributed by NM, 2-Mar-2004) (Revised by Mario Carneiro, 23-Dec-2013) (New usage is discouraged.)

Ref Expression
Assertion sshjval3 A B A B = A B

Proof

Step Hyp Ref Expression
1 ax-hilex V
2 1 elpw2 A 𝒫 A
3 1 elpw2 B 𝒫 B
4 uniprg A 𝒫 B 𝒫 A B = A B
5 2 3 4 syl2anbr A B A B = A B
6 5 fveq2d A B A B = A B
7 6 fveq2d A B A B = A B
8 prssi A 𝒫 B 𝒫 A B 𝒫
9 2 3 8 syl2anbr A B A B 𝒫
10 hsupval A B 𝒫 A B = A B
11 9 10 syl A B A B = A B
12 sshjval A B A B = A B
13 7 11 12 3eqtr4rd A B A B = A B