## Article

```catala
declaration scope S:
  context output a content A
  context output b content B

declaration structure A:
   data x content decimal
   data y content B

declaration structure B:
   data y content boolean
   data z content decimal

scope S:
   definition b equals let b equals 42 in B { -- y: true -- z: integer_to_decimal of b}
   definition a equals
     let b equals
       if b.B.y
       then B { -- y: false -- z: -1. }
       else B { -- y: true  -- z: -2. }
     in
     let a equals 2. *. b.z in
     A { -- x: a -- y : b }
```

```catala-test-inline
$ catala Interpret -s S
[RESULT] Computation successful! Results:
[RESULT] a = A { "x"= -2.; "y"= B { "y"= false; "z"= -1. } }
[RESULT] b = B { "y"= true; "z"= 42. }
```

## Check scope of let-in vs scope variable

```catala
declaration scope S2:
   x scope S
   output y content integer

scope S2:
  definition y equals
    let x equals 0 in
    x + 1
```

```catala-test-inline
$ catala Interpret -s S2
[RESULT] Computation successful! Results:
[RESULT] y = 1
```