Definition df-oprab 5922

Description: Define the class abstraction (class builder) of a collection of nested ordered pairs (for use in defining operations). This is a special case of Definition 4.16 of [TakeutiZaring] p. 14. Normally x, y, and z are distinct, although the definition doesn't strictly require it. See df-ov 5921 for the value of an operation. The brace notation is called "class abstraction" by Quine; it is also called a "class builder" in the literature. The value of the most common operation class builder is given by ovmpo 6054. (Contributed by NM, 12-Mar-1995.)

Assertion

Ref	Expression
df-oprab	|- { <. <. x , y >. , z >. | ph } = { w | E. x E. y E. z ( w = <. <. x , y >. , z >. /\ ph ) }

Distinct variable groups:   x, w   y, w   z, w   ph, w

Allowed substitution hints:   ph( x, y, z)

Detailed syntax breakdown of Definition df-oprab

Step	Hyp	Ref	Expression
1		wph	. . 3 wff ph
2		vx	. . 3 setvar x
3		vy	. . 3 setvar y
4		vz	. . 3 setvar z
5	1, 2, 3, 4	coprab 5919	. 2 class { <. <. x , y >. , z >. | ph }
6		vw	. . . . . . . . 9 setvar w
7	6	cv 1363	. . . . . . . 8 class w
8	2	cv 1363	. . . . . . . . . 10 class x
9	3	cv 1363	. . . . . . . . . 10 class y
10	8, 9	cop 3621	. . . . . . . . 9 class <. x , y >.
11	4	cv 1363	. . . . . . . . 9 class z
12	10, 11	cop 3621	. . . . . . . 8 class <. <. x , y >. , z >.
13	7, 12	wceq 1364	. . . . . . 7 wff w = <. <. x , y >. , z >.
14	13, 1	wa 104	. . . . . 6 wff ( w = <. <. x , y >. , z >. /\ ph )
15	14, 4	wex 1503	. . . . 5 wff E. z ( w = <. <. x , y >. , z >. /\ ph )
16	15, 3	wex 1503	. . . 4 wff E. y E. z ( w = <. <. x , y >. , z >. /\ ph )
17	16, 2	wex 1503	. . 3 wff E. x E. y E. z ( w = <. <. x , y >. , z >. /\ ph )
18	17, 6	cab 2179	. 2 class { w | E. x E. y E. z ( w = <. <. x , y >. , z >. /\ ph ) }
19	5, 18	wceq 1364	1 wff { <. <. x , y >. , z >. | ph } = { w | E. x E. y E. z ( w = <. <. x , y >. , z >. /\ ph ) }

This definition is referenced by:  oprabid  5950  dfoprab2  5965  nfoprab1  5967  nfoprab2  5968  nfoprab3  5969  nfoprab  5970  oprabbid  5971  ssoprab2  5974  mpo0  5988  cbvoprab2  5991  eloprabga  6005  oprabrexex2  6182  eloprabi  6249  cnvoprab  6287  dftpos3  6315