Index: tol/bmath/mathobjects/tol_bdat.h
===================================================================
--- tol/bmath/mathobjects/tol_bdat.h	(revision 437b27728294188763a242de99c761c5ec81f872)
+++ tol/bmath/mathobjects/tol_bdat.h	(revision 47f978d25cc64be1d6abf38163314d2ede0a98de)
@@ -129,9 +129,10 @@
   static BReal Nan()     { return(nan_); }
   //! Return \a unknown_ attribute
-  static BDat& Unknown ()      { return(unknown_); }
+  static BDat Unknown ()      { return(unknown_); }
+//static const BDat& Unknown ()      { return(unknown_=); }
   //! Return \a piNumber_ attribute
-  static BDat& Pi ()           { return(piNumber_); }
+  static BDat Pi ()           { return(piNumber_); }
   //! Return \a eNumber_ attribute
-  static BDat& E ()            { return(eNumber_); }
+  static BDat E ()            { return(eNumber_); }
   //! Return \a maxIter_ attribute
   static BDat& MaxIter ()      { return(maxIter_); }
@@ -141,5 +142,5 @@
   static BDat& RelTolerance () { return(relTolerance_); }
   //! Return \a zero_ attribute
-  static BDat& Zero ()         { return(zero_); }
+  static BDat Zero ()         { return(zero_); }
 
   //! Saves the number of the committed error