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# -(_:_:)

Subtracts one value from another and produces their difference.

```
static func - (a: UInt128, b: UInt128) -> UInt128
```

## Discussion

The subtraction operator (`-`) calculates the difference of its two
arguments. For example:

```
8 - 3                   // 5
-10 - 5                 // -15
100 - -5                // 105
10.5 - 100.0            // -89.5
```

You cannot use `-` with arguments of different types. To subtract values
of different types, convert one of the values to the other value’s type.

```
let x: UInt8 = 21
let y: UInt = 1000000
y - UInt(x)             // 999979
```

---

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