bash 'if [[ <cond> ]]; then ...fi' should 'then' be redundant?

[Vang Le-Quy]

Ever since I wrote my first bash `if`, I was told to immediately use `then`. 
This structure become so familiar:

```
if  [[ <condition> ]]; then
                statements
else
                statements
fi

```

There might be a historical reason for `then` to be in there. But would it just 
be straight forward without `then`? What is ambiguous about it?


```
if  [[ <condition> ]]
                statements
else
                statements
fi

```


Kind regards
Vang