Metamath Proof Explorer


Definition df-md

Description: Define the modular pair relation (on the Hilbert lattice). Definition 1.1 of MaedaMaeda p. 1, who use the notation (x,y)M for "the ordered pair is a modular pair." See mdbr for membership relation. (Contributed by NM, 14-Jun-2004) (New usage is discouraged.)

Ref Expression
Assertion df-md 𝑀 = x y | x C y C z C z y z x y = z x y

Detailed syntax breakdown

Step Hyp Ref Expression
0 cmd class 𝑀
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 vz setvar z
10 9 cv setvar z
11 10 6 wss wff z y
12 chj class
13 10 3 12 co class z x
14 13 6 cin class z x y
15 3 6 cin class x y
16 10 15 12 co class z x y
17 14 16 wceq wff z x y = z x y
18 11 17 wi wff z y z x y = z x y
19 18 9 4 wral wff z C z y z x y = z x y
20 8 19 wa wff x C y C z C z y z x y = z x y
21 20 1 2 copab class x y | x C y C z C z y z x y = z x y
22 0 21 wceq wff 𝑀 = x y | x C y C z C z y z x y = z x y