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# BidirectionalCollection Implementations

## Topics

### Instance Properties

[`var endIndex: MarkupOrderedSet.Index`](/documentation/PaperKit/MarkupOrderedSet/endIndex)

The index past the last element in the set.

[`var startIndex: MarkupOrderedSet.Index`](/documentation/PaperKit/MarkupOrderedSet/startIndex)

The index of the first element in the set.

### Instance Methods

[`func index(after: MarkupOrderedSet.Index) -> MarkupOrderedSet.Index`](/documentation/PaperKit/MarkupOrderedSet/index(after:))

Returns the index immediately after the given index.

### Subscripts

[`subscript(Int) -> MarkupOrderedSet.Element`](/documentation/PaperKit/MarkupOrderedSet/subscript(_:)-3x3ly)

Accesses the element at the specified position.

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