c# internal abstract class

how will i access members of  internal abstract  class in another class with different name space.

sample ->

file name = a.cs
namespace xyz
{
internal abstract  class bm
    {
      public   bool abc(bool userDefined)
        {
            return true;
      }
   }
}



file name = b.cs

namespace ppp
{
    internal class kl  :    gh   // 2.2
    {
        private xyz.bm  b160 =  null ;    // i did this
      bool b0 = true;

       public void updateFeature(bool Check)  
        {
     
                b0 = this.b160.abc(Check);
             
       
        }

    }
}