##Return two copies of an expression

If you want to get two copies of the result of an expression, you can use this:

$v.$v=expr

But it won't be shorter than the more straightforward ($v=expr).$v if you need to append more things to the result.

For 4 copies:

$v.$v.=$v=expr

You cannot use it to get 3 copies.

Return two copies of an expression

If you want to get two copies of the result of an expression, you can use this:

$v.$v=expr

But it won't be shorter than the more straightforward ($v=expr).$v if you need to append more things to the result.

For 4 copies:

$v.$v.=$v=expr

You cannot use it to get 3 copies.