默认情况下，Elvish（macOS，Homebrew）有一个基本的PATH定义：

~> echo $paths
[/usr/bin /bin /usr/sbin /sbin]

我想向它添加/usr/local/bin和/usr/local/sbin项，但不从头开始编写文字，如

set paths = [/usr/bin /bin /usr/sbin /sbin /usr/local/bin /usr/local/sbin]

更常见的贝壳的基本模式当然是

export PATH="/usr/local/bin:/usr/local/sbin:$PATH"

精灵语中的列表是不可变的，所以我想做一些类似

set paths = paths + [/usr/local/bin /usr/local/sbin]

但是我在文档中没有找到任何东西，我的尝试失败了：

~> set paths = paths + [/usr/local/bin /usr/local/sbin]
Exception: arity mismatch: assignment right-hand-side must be 1 value, but is 3 values
[tty 2]:1:1: set paths = paths + [/usr/local/bin /usr/local/sbin]

~> set paths = [$paths /usr/local/bin /usr/local/sbin]
Exception: path must be string
[tty 3]:1:5: set paths = [$paths /usr/local/bin /usr/local/sbin]