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Related theorems Unicode version |
| Description: The value of a class exists. Corollary 6.13 of [TakeutiZaring] p. 27. |
| Ref | Expression |
|---|---|
| fvex |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-fv 3193 |
. 2
| |
| 2 | moeq 1916 |
. . . . 5
| |
| 3 | unieq 2505 |
. . . . . . 7
| |
| 4 | visset 1809 |
. . . . . . . 8
| |
| 5 | 4 | unisn 2512 |
. . . . . . 7
|
| 6 | 3, 5 | syl6req 1521 |
. . . . . 6
|
| 7 | 6 | immoi 1416 |
. . . . 5
|
| 8 | 2, 7 | ax-mp 7 |
. . . 4
|
| 9 | moabex 2761 |
. . . 4
| |
| 10 | 8, 9 | ax-mp 7 |
. . 3
|
| 11 | 10 | uniex 2865 |
. 2
|
| 12 | 1, 11 | eqeltr 1541 |
1
|