a bit more documentation copied from Java

src/runtime/dotNet/Bracket.cs

@@ -16,7 +16,10 @@ namespace PGFSharp
 		Bracket AsBracketChild {get;}
 	}
 
-
+	/// <summary>
+	/// A representation for a syntactic constituent in the parse tree
+    /// of a sentence.
+    /// </summary>
 	public class Bracket : IBracketChild
     {
 		public class StringChildBracket : IBracketChild {

src/runtime/dotNet/Concr.cs

@@ -8,7 +8,7 @@ using System.Runtime.InteropServices;
 namespace PGFSharp
 {
     /// <summary>
-    /// Concrete grammar. All concrete grammars are available from the (Abstract) <see cref="Grammar"/> class.
+    /// The class for concrete syntaxes.
     /// </summary>
     public class Concr
     {

src/runtime/dotNet/Expr.cs

@@ -16,6 +16,9 @@ namespace PGFSharp
         }
     }
 
+	/// <summary>
+	/// A representation for an abstract syntax tree.
+	/// </summary>
     public abstract class Expr
     {
         internal IntPtr DataPtr => NativeGU.gu_variant_open(_ptr).Data; // PgfExprLit* 

src/runtime/dotNet/PGF.cs

@@ -8,7 +8,7 @@ using System.Threading.Tasks;
 namespace PGFSharp
 {
     /// <summary>
-    /// This is the class for PGF grammars.
+    /// The class for PGF grammars.
     /// </summary>
     public class PGF
     {

src/runtime/dotNet/Type.cs

@@ -8,7 +8,7 @@ using System.Threading.Tasks;
 namespace PGFSharp
 {
     /// <summary>
-    /// A GF type.
+    /// A class for types in the abstract syntax of a grammar.
     /// </summary>
     public class Type
     {