Get a slice from an array
# Arguments
- a_min : A start index ( trimmed )
- a_max : A end index ( trimmed )
- a_array : An array to process
# Demo
```
% This may look very confusing because it is
$slice(0,3,1,2,3,4)
===
1,2,3,4
```
# Example
$assert(\\*2,3*\\,$slice(1,2,1,2,3,4,5,6))