# SigmaSnd::inhabitation-failed


**Key:** `SigmaSnd::inhabitation-failed`

**Category:** inhabitation · **Severity:** error

**Source:** [`src/diag/hints.nix:914`](https://github.com/kleisli-io/nix-effects/blob/main/src/diag/hints.nix#L914)

the second component does not inhabit the dependent `snd` type

## Example

`Hint::SigmaSnd::inhabitation-failed` means the `SigmaSnd` position contains a value that does not inhabit the generated type. The example shows the failing form first, then one way to give the checker the missing structure.

```nix
# Bad: the second component does not inhabit snd's dependent type.
pair (natLit 3) "not-a-proof"

# Better: snd inhabits the type determined by fst.
pair (natLit 3) proofFor3

```


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