## Article

```catala
declaration enumeration E:
  -- Case1 content integer
  -- Case2

declaration scope A:
  internal x content E
  output y content integer

scope A:
  definition x equals Case1 content 2
  definition y under condition match x with pattern
    -- Case1 of i : true
    -- Case2 : false consequence equals 2
  definition y under condition match x with pattern
    -- Case1 of i : false
    -- Case2 : true consequence equals 2
```



```catala-test-inline
$ catala Typecheck --check-invariants
┌─[RESULT]─
│ All invariant checks passed
└─
┌─[RESULT]─
│ Typechecking successful!
└─
```

```catala-test-inline
$ catala Proof --disable-counterexamples 
┌─[RESULT]─
│ No errors found during the proof mode run.
└─
```