An Expression or mathematical expression is a finite combination of symbols that is well-formed according to rules that depend on the context. Expressions are special because they are evaluated before sending the result to a channel.

The following operators are used for building expressions:

The supported arithmetic operators are: `+`

, `-`

, `/`

, `*`

.

The supported relational operators are: `>`

, `>=`

, `<`

, `<=',`

==`,`

!=`.

The supported logical operators are: `and`

, `or`

, `not`

.

The `p matches q`

expression is similar to

```
match p {
q -> true
_ -> false
}
```

The difference between `matches`

and the above is that the former is an expression.