Description: The inverse image of the universal class _V under the base function is the universal class _V itself. (Proposed by Mario Carneiro, 7-Mar-2020.) (Contributed by AV, 7-Mar-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | bascnvimaeqv | ⊢ ( ◡ Base “ V ) = V |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | basfn | ⊢ Base Fn V | |
| 2 | fncnvimaeqv | ⊢ ( Base Fn V → ( ◡ Base “ V ) = V ) | |
| 3 | 1 2 | ax-mp | ⊢ ( ◡ Base “ V ) = V |