// A host paragraph to hold the example Inline elements..
Paragraph par = new Paragraph();

// Some arbitrary Inline elements.
Run run1 = new Run("Text run number 1.");
Run run2 = new Run("Text run number 2.");
Bold bold = new Bold(new Run("Bold text."));
Italic ital = new Italic(new Run("Italic text."));
Span span1 = new Span(new Run("Span number 1"));
Span span2 = new Span(new Run("Span number 2"));

// Add the Inline elements to the Paragraph. Note the order
// of the inline elements in the paragraph; the order is 
// arbitrary, but the notion of an order is important with 
// respect to  what are 'previous' and 'next' elements.
par.Inlines.Add(run1);
par.Inlines.Add(run2);
par.Inlines.Add(bold);
par.Inlines.Add(ital);
par.Inlines.Add(span1);
par.Inlines.Add(span2);

// After this line executes, "nextSibling" holds "run2", which is
// the next peer-level Inline following "run1".
Inline nextSibling = run1.NextInline;

// After this line executes, "nextSibling" holds "span1", which is
// the next peer-level Inline following "ital".
nextSibling = ital.NextInline;

// After this line executes, "nextSibling" is null, since "span2" is the
// last Inline element in the Paragraph.
nextSibling = span2.NextInline;