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| Description: Define the cross product of two classes. Definition 9.11 of [Quine] p. 64. |
| Ref | Expression |
|---|---|
| df-xp |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cA |
. . 3
| |
| 2 | cB |
. . 3
| |
| 3 | 1, 2 | cxp 3249 |
. 2
|
| 4 | vx |
. . . . . 6
| |
| 5 | 4 | cv 991 |
. . . . 5
|
| 6 | 5, 1 | wcel 994 |
. . . 4
|
| 7 | vy |
. . . . . 6
| |
| 8 | 7 | cv 991 |
. . . . 5
|
| 9 | 8, 2 | wcel 994 |
. . . 4
|
| 10 | 6, 9 | wa 221 |
. . 3
|
| 11 | 10, 4, 7 | copab 2740 |
. 2
|
| 12 | 3, 11 | wceq 992 |
1
|
| Colors of variables: wff set class |
| This definition is referenced by: xpeq1 3281 xpeq2 3282 elxp 3283 fconstopab 3293 xpundi 3310 xpundir 3311 opabssxp 3320 relopab 3357 dmxp 3419 resopab 3485 1st2val 4158 2nd2val 4159 aceq3 4879 genpdm 5259 infmap2lem2 7792 ajfval 8724 inposet 10868 domncnt 10872 ranncnt 10873 filnetlem4 11766 filnet 11768 |