# ::unhandled-boot-inr


**Key:** `::unhandled-boot-inr`

**Category:** shape · **Severity:** error

**Source:** [`src/diag/hints.nix:947`](https://github.com/kleisli-io/nix-effects/blob/main/src/diag/hints.nix#L947)

the right injection `inr y` has no inference rule — the sum type's left summand is not determined by the syntax of `y` alone. Annotate with `ann (inr y) (sum A B)` to fix the expected sum, or place it where checking already provides one.

## Example

`Hint::unhandled-boot-inr` means `inr` is in inference mode without an expected Sum type. The example shows the failing form first, then one way to give the checker the missing structure.

```nix
# Bad: inr does not determine the left summand by itself.
infer emptyCtx (inr true_)

# Better: annotate the intended sum type.
infer emptyCtx (ann (inr true_) (sum nat bool))

```


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