diff --git a/src/mathed/math_diminset.C b/src/mathed/math_diminset.C
new file mode 100644
index 0000000000..f3065be8e3
--- /dev/null
+++ b/src/mathed/math_diminset.C
@@ -0,0 +1,24 @@
+#include "math_diminset.h"
+
+
+MathDimInset::MathDimInset()
+	: width_(0), ascent_(0), descent_(0)
+{}
+
+
+int MathDimInset::ascent() const
+{
+	return ascent_;
+}
+
+
+int MathDimInset::descent() const
+{
+	return descent_;
+}
+
+
+int MathDimInset::width() const
+{
+	return width_;
+}
diff --git a/src/mathed/math_diminset.h b/src/mathed/math_diminset.h
new file mode 100644
index 0000000000..931efa9f4b
--- /dev/null
+++ b/src/mathed/math_diminset.h
@@ -0,0 +1,26 @@
+// -*- C++ -*-
+#ifndef MATH_DIMINSET_H
+#define MATH_DIMINSET_H
+
+#include "math_inset.h"
+
+/// thing that need the dimension cache
+class MathDimInset : public MathInset {
+public:
+	MathDimInset();
+	/// 
+	int ascent() const;
+	///
+	int descent() const;
+	///
+	int width() const;
+
+protected:
+	///
+	int width_;
+	///
+	int ascent_;
+	///
+	int descent_;
+};
+#endif