Metamath Proof Explorer


Definition df-cv

Description: Define the covers relation (on the Hilbert lattice). Definition 3.2.18 of PtakPulmannova p. 68, whose notation we use. Ptak/Pulmannova's notation A is read " B covers A " or " A is covered by B " , and it means that B is larger than A and there is nothing in between. See cvbr and cvbr2 for membership relations. (Contributed by NM, 4-Jun-2004) (New usage is discouraged.)

Ref Expression
Assertion df-cv = x y | x C y C x y ¬ z C x z z y

Detailed syntax breakdown

Step Hyp Ref Expression
0 ccv class
1 vx setvar x
2 vy setvar y
3 1 cv setvar x
4 cch class C
5 3 4 wcel wff x C
6 2 cv setvar y
7 6 4 wcel wff y C
8 5 7 wa wff x C y C
9 3 6 wpss wff x y
10 vz setvar z
11 10 cv setvar z
12 3 11 wpss wff x z
13 11 6 wpss wff z y
14 12 13 wa wff x z z y
15 14 10 4 wrex wff z C x z z y
16 15 wn wff ¬ z C x z z y
17 9 16 wa wff x y ¬ z C x z z y
18 8 17 wa wff x C y C x y ¬ z C x z z y
19 18 1 2 copab class x y | x C y C x y ¬ z C x z z y
20 0 19 wceq wff = x y | x C y C x y ¬ z C x z z y