         
                    Cartesian
            
                </a>
            

            
            <ul class="articles">
                
    
        <li class="chapter active" data-level="1.6.1.1" data-path="category.html">
            
                <a href="category.html">
            
                    
                    Category
            
                </a>
            

            
        </li>
    
        <li class="chapter " data-level="1.6.1.2" data-path="linear.html">
