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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 3175 |
. 2
|
| 4 | vx |
. . . . . 6
| |
| 5 | 4 | cv 957 |
. . . . 5
|
| 6 | 5, 1 | wcel 960 |
. . . 4
|
| 7 | vy |
. . . . . 6
| |
| 8 | 7 | cv 957 |
. . . . 5
|
| 9 | 8, 2 | wcel 960 |
. . . 4
|
| 10 | 6, 9 | wa 223 |
. . 3
|
| 11 | 10, 4, 7 | copab 2672 |
. 2
|
| 12 | 3, 11 | wceq 958 |
1
|
| Colors of variables: wff set class |
| This definition is referenced by: xpeq1 3207 xpeq2 3208 elxp 3209 fconstopab 3217 xpundi 3232 xpundir 3233 opabssxp 3241 relopab 3273 dmxp 3339 resopab 3402 1st2val 4102 2nd2val 4103 aceq3 4750 genpdm 5124 infmap2lem2 7589 ajfval 8472 inposet 10485 |