# Proof

### Definition

A Proof is any additional document needed to verify or support information provided in the [case](https://docs.atfinity.io/guides/glossary/case).

Like a document, a proof has a condition. The proof only becomes part of a case if the condition is true.

### Example

Typical examples of proofs are a passport scan, a wealth origin report or a company organisational chart. If e.g. a passport scan is required whenever a client is not Swiss, then the proof 'Passport Scan' would have a condition like this:

```
p is Person

p.nationality != che
```

Now every time, there is a person involved in a case who's nationality is not Swiss (che) Atfinity will ask to provide a scan of this person's passport.