diff --git a/Grid_main.cc b/Grid_main.cc
index 13c3d9ee..8cac55f5 100644
--- a/Grid_main.cc
+++ b/Grid_main.cc
@@ -14,10 +14,10 @@ int main (int argc, char ** argv)
   std::vector<int> simd_layout(4);
   
   std::vector<int> mpi_layout(4);
-  mpi_layout[0]=2;
-  mpi_layout[1]=2;
-  mpi_layout[2]=2;
-  mpi_layout[3]=2;
+  mpi_layout[0]=1;
+  mpi_layout[1]=1;
+  mpi_layout[2]=1;
+  mpi_layout[3]=1;
 
 #ifdef AVX512
  for(int omp=128;omp<236;omp+=16){
diff --git a/Grid_math_type_mapper.h b/Grid_math_type_mapper.h
index 856f2c6b..4e7120b1 100644
--- a/Grid_math_type_mapper.h
+++ b/Grid_math_type_mapper.h
@@ -10,6 +10,7 @@ namespace Grid {
     typedef typename T::scalar_type scalar_type;
     typedef typename T::vector_type vector_type;
     typedef typename T::tensor_reduced tensor_reduced;
+    //    enum { TensorLevel = T::TensorLevel };
   };
 
 //////////////////////////////////////////////////////////////////////////////////
@@ -20,24 +21,28 @@ namespace Grid {
     typedef RealF scalar_type;
     typedef RealF vector_type;
     typedef RealF tensor_reduced ;
+    //    enum { TensorLevel = 0 };
   };
   template<> class GridTypeMapper<RealD> {
   public:
     typedef RealD scalar_type;
     typedef RealD vector_type;
     typedef RealD tensor_reduced;
+    //    enum { TensorLevel = 0 };
   };
   template<> class GridTypeMapper<ComplexF> {
   public:
     typedef ComplexF scalar_type;
     typedef ComplexF vector_type;
     typedef ComplexF tensor_reduced;
+    //    enum { TensorLevel = 0 };
   };
   template<> class GridTypeMapper<ComplexD> {
   public:
     typedef ComplexD scalar_type;
     typedef ComplexD vector_type;
     typedef ComplexD tensor_reduced;
+    //    enum { TensorLevel = 0 };
   };
 
   template<> class GridTypeMapper<vRealF> {
@@ -45,30 +50,35 @@ namespace Grid {
     typedef RealF  scalar_type;
     typedef vRealF vector_type;
     typedef vRealF tensor_reduced;
+    //    enum { TensorLevel = 0 };
   };
   template<> class GridTypeMapper<vRealD> {
   public:
     typedef RealD  scalar_type;
     typedef vRealD vector_type;
     typedef vRealD tensor_reduced;
+    //enum { TensorLevel = 0 };
   };
   template<> class GridTypeMapper<vComplexF> {
   public:
     typedef ComplexF  scalar_type;
     typedef vComplexF vector_type;
     typedef vComplexF tensor_reduced;
+    //enum { TensorLevel = 0 };
   };
   template<> class GridTypeMapper<vComplexD> {
   public:
     typedef ComplexD  scalar_type;
     typedef vComplexD vector_type;
     typedef vComplexD tensor_reduced;
+    //enum { TensorLevel = 0 };
   };
   template<> class GridTypeMapper<vInteger> {
   public:
     typedef Integer  scalar_type;
     typedef vInteger vector_type;
     typedef vInteger tensor_reduced;
+    //enum { TensorLevel = 0 };
   };
 
   // Again terminate the recursion.
diff --git a/Grid_math_types.h b/Grid_math_types.h
index 01fc7bf2..db90bda7 100644
--- a/Grid_math_types.h
+++ b/Grid_math_types.h
@@ -19,6 +19,7 @@ public:
   typedef typename GridTypeMapper<vtype>::scalar_type scalar_type;
   typedef typename GridTypeMapper<vtype>::vector_type vector_type;
   typedef typename GridTypeMapper<vtype>::tensor_reduced tensor_reduced_v;
+  //enum { TensorLevel = GridTypeMapper<vtype>::TensorLevel + 1};
   typedef iScalar<tensor_reduced_v> tensor_reduced;
 
 
@@ -78,6 +79,7 @@ public:
   typedef typename GridTypeMapper<vtype>::scalar_type scalar_type;
   typedef typename GridTypeMapper<vtype>::vector_type vector_type;
   typedef typename GridTypeMapper<vtype>::tensor_reduced tensor_reduced_v;
+  //  enum { TensorLevel = GridTypeMapper<vtype>::TensorLevel + 1};
   typedef iScalar<tensor_reduced_v> tensor_reduced;
 
 
@@ -136,6 +138,7 @@ public:
   typedef typename GridTypeMapper<vtype>::scalar_type scalar_type;
   typedef typename GridTypeMapper<vtype>::vector_type vector_type;
   typedef typename GridTypeMapper<vtype>::tensor_reduced tensor_reduced_v;
+  //  enum { TensorLevel = GridTypeMapper<vtype>::TensorLevel + 1};
   typedef iScalar<tensor_reduced_v> tensor_reduced;
 
   iMatrix(Zero &z){ *this = zero; };
diff --git a/Grid_simd.h b/Grid_simd.h
index 4f9f4b0d..f0cf6c08 100644
--- a/Grid_simd.h
+++ b/Grid_simd.h
@@ -273,10 +273,16 @@ namespace Grid {
    inline void add (vRealD *__restrict__ y,const vRealD *__restrict__ l,const RealD *__restrict__ r){ *y = (*l) + (*r); }
 
   // Default precision
-  typedef RealD  Real;
-  typedef std::complex<Real>  Complex;
-
+#ifdef GRID_DEFAULT_PRECISION_DOUBLE
+  typedef RealD   Real;
   typedef vRealD vReal;
   typedef vComplexD vComplex;
+  typedef std::complex<Real>  Complex;
+#else
+  typedef RealF  Real;
+  typedef vRealF vReal;
+  typedef vComplexF vComplex;
+  typedef std::complex<Real>  Complex;
+#endif
 }
 #endif
diff --git a/Grid_vComplexF.h b/Grid_vComplexF.h
index 9dc5f051..75c47248 100644
--- a/Grid_vComplexF.h
+++ b/Grid_vComplexF.h
@@ -373,6 +373,8 @@ friend inline void vstore(const vComplexF &ret, ComplexF *a){
     {
         return l*r;
     }
-
+    inline vComplexF trace(const vComplexF &arg){
+        return arg;
+    }
 }
 #endif
diff --git a/Grid_vRealD.h b/Grid_vRealD.h
index 84c80698..86f738f3 100644
--- a/Grid_vRealD.h
+++ b/Grid_vRealD.h
@@ -247,6 +247,9 @@ namespace Grid {
     {
         return l*r;
     }
+    inline vRealD trace(const vRealD &arg){
+        return arg;
+    }
 
 
 }
diff --git a/Grid_vRealF.h b/Grid_vRealF.h
index aeb454f0..b7c127ce 100644
--- a/Grid_vRealF.h
+++ b/Grid_vRealF.h
@@ -268,6 +268,9 @@ friend inline void vstore(const vRealF &ret, float *a){
         return l*r;
     }
 
+    inline vRealF trace(const vRealF &arg){
+        return arg;
+    }
 
     
 }