# Feature: `meval` calculator without variables
A <em>simple</em> spec for a calculator based on the `meval` Rust crate that
doesn't use variables.
## Example: Addition
When `input` is:
```
2 * 5
```
Then `result` is:
```
10
```
## Example: `pi`
When `input` is:
```
2 * pi
```
Then `result` is:
```
6.283185307179586
```
## Builtin functions
The calculator provides various builtin functions.
### Background
Given `x` as:
```
7
```
And `y` as:
```
3
```
## Example: min/max
When `input` is:
```
min(x, y)
```
Then `result` is:
```
3
```