# --, == ยท Terminators
The `--` and `==` are used as terminators: `--` for core expressions, and `==` for terminating a 'running' or 'jogging' series of Hoon expressions.
## -- "hephep"
#### Syntax
The `--` rune is used to indicate the end of a core expression.
#### Discussion
The `|%`, `|_`, and `|^` runes are used to create cores that can have arbitrarily many arms. When you have defined all the desired arms in a core expression (using the `++`, `+$`, and `+*` runes), use `--` to terminate the expression.
#### Examples
```
> =num |%
++ two 2
++ add-two |=(a=@ (add 2 a))
++ double |=(a=@ (mul 2 a))
--
> two.num
2
> (add-two.num 12)
14
> (double.num 12)
24
```
***
## == "tistis"
#### Syntax
The `==` rune is used to indicate the end of a 'jogging' or 'running' series of Hoon expressions (runes that take a variable number of arguments).
#### Discussion
Certain runes are used to create expressions that may include arbitrarily many subexpressions. Such expressions are terminated with the `==` rune. For example, the `:*` and `:~` runes are used to create a cell of any length. (The latter is just like the former except that it adds a null value at the end of the cell.) For another example, the `%=` rune used used to make arbitrarily many changes to a given wing value.
#### Examples
```
> :* 2
3
4
5
6
==
[2 3 4 5 6]
> :~ 2
3
4
5
6
==
[2 3 4 5 6 ~]
> =values [a=12 b=14 c=16 d=18 e=20]
> %= values
a 13
b 15
c 17
d 19
e 21
==
[a=13 b=15 c=17 d=19 e=21]
```