> ## Documentation Index
> Fetch the complete documentation index at: https://developers.kardinal.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Hard vs soft constraints

> Feasibility logic and why a problem can be declared infeasible.

<Note>
  Explanation — priority P0. Linked to the "Handling infeasibility" how-to guide.
</Note>

## To be written

* Definition of a hard constraint (must be respected) vs soft (respected if possible)
* Examples of each type in the Kardinal model
* How the engine arbitrates in case of conflict
* Why a problem is declared infeasible