Possible answer to SO 39451235 (http://stackoverflow.com/q/39451235/471780)

so-39451235_roslyn-find-usingdirectivesyntax-that-belongs-to-invocationexpressionsyntax.linq

<Query Kind="Statements">
  <NuGetReference>Microsoft.CodeAnalysis</NuGetReference>
  <NuGetReference>Microsoft.CodeAnalysis.CSharp</NuGetReference>
  <Namespace>Microsoft.CodeAnalysis</Namespace>
  <Namespace>Microsoft.CodeAnalysis.CSharp.Syntax</Namespace>
  <Namespace>Microsoft.CodeAnalysis.MSBuild</Namespace>
  <Namespace>Microsoft.CodeAnalysis.CSharp</Namespace>
  <Namespace>Microsoft.CodeAnalysis.Formatting</Namespace>
  <Namespace>Microsoft.CodeAnalysis.Text</Namespace>
</Query>

// possible answer to: http://stackoverflow.com/q/39451235/471780

// create tree, and semantic model
var tree = CSharpSyntaxTree.ParseText(@"
	using System;
	public class Program
	{
	   public static void Main()
	   {
	      Console.WriteLine(""Hello World"");
	   }
   }");
var root = tree.GetRoot();

var mscorlib = MetadataReference.CreateFromFile(typeof(object).Assembly.Location);
var compilation = CSharpCompilation.Create("SO-39451235", syntaxTrees: new[] { tree }, references: new[] { mscorlib });
var model = compilation.GetSemanticModel(tree);

// get the nodes refered to in the SO question

var usingSystemDirectiveNode = root.DescendantNodes().OfType<UsingDirectiveSyntax>().Single();
var consoleWriteLineInvocationNode = root.DescendantNodes().OfType<InvocationExpressionSyntax>().Single();

// retrieve symbols related to the syntax nodes

var writeLineMethodSymbol = (IMethodSymbol)model.GetSymbolInfo(consoleWriteLineInvocationNode).Symbol;
var namespaceOfWriteLineMethodSymbol = (INamespaceSymbol)writeLineMethodSymbol.ContainingNamespace;

var usingSystemNamespaceSymbol = model.GetSymbolInfo(usingSystemDirectiveNode.Name).Symbol;

// check the namespace symbols for equality, this will return true

namespaceOfWriteLineMethodSymbol.Equals(usingSystemNamespaceSymbol).Dump();