Java XML design boolean flag and values

Here is what my current XML file looks like.

<book>
    <isWritable>true</isWritable>
    <writeDelay>4.0</writeDelay>

    <isReadable>true</isReadable>
    <readDelay>3.2</readDelay>

    <isDestroyed>false</isDestroyed>
</book>

I have:

3 boolean flags - isWritable, isReadable, isDestroyed.

2 values writeDelay, readDelay.

Conditions:

isWritable require writeDelay

isReadable require readDelay

You can be isDestroyed but not isWritable or isReadable

You can be isWriteable and isReadable

You can be isWritable or isReadable

Current implementaion:

Book.class has all of these has required fields. I'm looking to simplifying this.

If my book is readable but not writable. The XML file should only be:

<book>
    <isReadable>true</isReadable>
    <readDelay>3.2</readDelay>
</book>

Likewise if the book is destroyed. The XML should only be:

<book>
    <isDestroyed>true</isDestroyed>
</book>

Is there any existing design pattern that applies to my situation? I have looked at a few and am leaning towards polymorphism but wanted to reach out to see if there are any other patterns I have not yet considered.

Any comments and suggestions will be appreciated. Thank you!