Index: src/SkalarFunction.cc
===================================================================
--- src/SkalarFunction.cc	(revision 164)
+++ src/SkalarFunction.cc	(working copy)
@@ -18,6 +18,9 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <tbb/tbb.h>
+#include <time.h>
+
 #include "SkalarFunction.hh"
 #include "Value.hh"
 #include "Workspace.hh"
@@ -57,27 +60,54 @@
 Bif_F12_WITHOUT   Bif_F12_WITHOUT::fun;
 
 //-----------------------------------------------------------------------------
+
+class ApplyRavel {
+public:
+    ApplyRavel( SkalarFunction &function_in,
+                Value_P &B_in,
+                Value_P &Z_in,
+                prim_f1 &fun_in )
+        : function( function_in ), B( B_in ), Z( Z_in ), fun( fun_in ) {}
+
+    void operator()( const tbb::blocked_range<ShapeItem> &range ) const {
+        for( ShapeItem c = range.begin() ; c != range.end() ; c++ ) {
+            const Cell * cell_B =  &B->get_ravel(c);
+            Cell * cell_Z = &Z->get_ravel(c);
+            if (cell_B->is_pointer_cell())
+            {
+                Token token = function.eval_skalar_B(cell_B->get_pointer_value(), fun);
+                new (cell_Z) PointerCell(token.get_apl_val());
+            }
+            else
+            {
+                (cell_B->*fun)(cell_Z);
+            }
+        }
+    }
+
+private:
+    SkalarFunction &function;
+    Value_P &B;
+    Value_P &Z;
+    prim_f1 &fun;
+};
+
 Token
 SkalarFunction::eval_skalar_B(Value_P B, prim_f1 fun)
 {
 const ShapeItem count = B->element_count();
    if (count == 0)   return eval_fill_B(B);
 
-Value_P Z(new Value(B->get_shape(), LOC));
-   loop(c, count)
-       {
-         const Cell * cell_B =  &B->get_ravel(c);
-         Cell * cell_Z = &Z->get_ravel(c);
-         if (cell_B->is_pointer_cell())
-            {
-              Token token = eval_skalar_B(cell_B->get_pointer_value(), fun);
-              new (cell_Z) PointerCell(token.get_apl_val());
-            }
-         else
-            {
-              (cell_B->*fun)(cell_Z);
-            }
-       }
+   Value_P Z;
+   if( B->is_temp() ) {
+       Z = B;
+   }
+   else {
+       Z = new Value(B->get_shape(), LOC);
+       Z->set_temp();
+   }
+//Value_P Z(new Value(B->get_shape(), LOC));
+//   Value_P Z(Zp);
 
    if (count == 0)   // Z was empty (hence B was empty)
       {
@@ -85,7 +115,36 @@
         if (cB.is_pointer_cell())   Z->get_ravel(0).init(cB);
         else                        new (&Z->get_ravel(0)) IntCell(0);
       }
+   else {
+       struct timespec start_ts, end_ts;
+       clock_gettime( CLOCK_REALTIME, &start_ts );
+#ifdef PARALLEL_DISABLED
+           loop(c, count)
+           {
+               const Cell * cell_B =  &B->get_ravel(c);
+               Cell * cell_Z = &Z->get_ravel(c);
+               if (cell_B->is_pointer_cell())
+               {
+                   Token token = eval_skalar_B(cell_B->get_pointer_value(), fun);
+                   new (cell_Z) PointerCell(token.get_apl_val());
+               }
+               else
+               {
+                   (cell_B->*fun)(cell_Z);
+               }
+           }
+#else
+           tbb::parallel_for( tbb::blocked_range<ShapeItem>( 0, count ), ApplyRavel( *this, B, Z, fun ) );
+#endif
 
+#if 0
+           clock_gettime( CLOCK_REALTIME, &end_ts );
+           long millis = (end_ts.tv_sec * 1000 + end_ts.tv_nsec / 1000000)
+               - (start_ts.tv_sec * 1000 + start_ts.tv_nsec / 1000000);
+           cout << "Total time: " << millis << endl;
+#endif
+   }
+
    Z->check_value(LOC);
    return Token(TOK_APL_VALUE1, Z);
 }
Index: src/Symbol.cc
===================================================================
--- src/Symbol.cc	(revision 164)
+++ src/Symbol.cc	(working copy)
@@ -126,7 +126,10 @@
    switch(vs.name_class)
       {
         case NC_UNUSED_USER_NAME:
-             new_value = new_value->clone(loc);
+            if( !new_value->is_temp() ) {
+                new_value = new_value->clone(loc);
+            }
+             new_value->clear_temp();
 
              vs.name_class = NC_VARIABLE;
              vs.apl_val = new_value;
@@ -136,7 +139,10 @@
         case NC_VARIABLE:
              if (vs.apl_val == new_value)   return;   // X←X
 
-             new_value = new_value->clone(loc);
+             if( !new_value->is_temp() ) {
+                 new_value = new_value->clone(loc);
+             }
+             new_value->clear_temp();
 
              // un-assign and erase old value
              //
Index: src/Value.cc
===================================================================
--- src/Value.cc	(revision 164)
+++ src/Value.cc	(working copy)
@@ -18,6 +18,8 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
+#include <tbb/tbb.h>
+
 #include "CDR_string.hh"
 #include "CharCell.hh"
 #include "Common.hh"
@@ -127,6 +129,7 @@
      flags(VF_NONE),
      valid_ravel_items(0)
 {
+    set_temp();
    ADD_EVENT(this, VHE_Create, 0, loc);
    init_ravel();
 }
@@ -136,6 +139,7 @@
      flags(VF_forever),
      valid_ravel_items(0)
 {
+    set_temp();
    // default shape is skalar
    //
    ADD_EVENT(this, VHE_Create, 0, loc);
@@ -249,6 +253,7 @@
      flags(VF_NONE),
      valid_ravel_items(0)
 {
+    set_temp();
    ADD_EVENT(this, VHE_Create, 0, loc);
    init_ravel();
 }
@@ -259,6 +264,7 @@
      flags(VF_NONE),
      valid_ravel_items(0)
 {
+    set_temp();
    ADD_EVENT(this, VHE_Create, 0, loc);
    init_ravel();
 
@@ -280,6 +286,7 @@
      flags(VF_NONE),
      valid_ravel_items(0)
 {
+    set_temp();
    ADD_EVENT(this, VHE_Create, 0, loc);
    init_ravel();
 
@@ -301,6 +308,7 @@
      flags(VF_NONE),
      valid_ravel_items(0)
 {
+    set_temp();
    ADD_EVENT(this, VHE_Create, 0, loc);
    init_ravel();
 
@@ -316,6 +324,7 @@
      flags(VF_NONE),
      valid_ravel_items(0)
 {
+    set_temp();
    ADD_EVENT(this, VHE_Create, 0, loc);
    init_ravel();
 }
@@ -325,6 +334,7 @@
      flags(VF_NONE),
      valid_ravel_items(0)
 {
+    set_temp();
    ADD_EVENT(this, VHE_Create, 0, loc);
    init_ravel();
 
@@ -1634,19 +1644,43 @@
 
 }
 //-----------------------------------------------------------------------------
+
+class ApplyClone {
+public:
+    ApplyClone( const Cell *src_in, Cell *dst_in ) : src( src_in ), dst( dst_in ) {}
+    void operator()( const tbb::blocked_range<size_t> &range ) const {
+        for( size_t p = range.begin() ; p != range.end() ; p++ ) {
+            dst[p].init( src[p] );
+        }
+    }
+
+private:
+    const Cell *src;
+    Cell *dst;
+};
+
 Value_P
 Value::clone(const char * loc) const
 {
-Value_P ret(new Value(get_shape(), loc));
+    if( is_temp() ) {
+        return Value_P( const_cast<Value *>( this ), LOC );
+    }
+    else {
+        Value_P ret(new Value(get_shape(), loc));
 
-const Cell * src = &get_ravel(0);
-Cell * dst = &ret->get_ravel(0);
-const ShapeItem count = nz_element_count();
+        const Cell * src = &get_ravel(0);
+        Cell * dst = &ret->get_ravel(0);
+        const ShapeItem count = nz_element_count();
 
-   loop(c, count)   dst++->init(*src++);
+#ifdef PARALLEL_DISABLED
+        loop(c, count)   dst++->init(*src++);
+#else
+        tbb::parallel_for( tbb::blocked_range<size_t>( 0, count ), ApplyClone( src, dst ) );
+#endif
 
-   ret->check_value(LOC);
-   return ret;
+        ret->check_value(LOC);
+        return ret;
+    }
 }
 //-----------------------------------------------------------------------------
 /// lrp p.138: S←⍴⍴A + NOTCHAR (per column)
Index: src/Value.hh
===================================================================
--- src/Value.hh	(revision 164)
+++ src/Value.hh	(working copy)
@@ -340,6 +340,7 @@
 
 # define clear_forever()  CLEAR_forever(_LOC)
 # define clear_marked()   CLEAR_marked(_LOC)
+# define clear_temp()     CLEAR_temp(_LOC);
 
    VF_flag(forever)
    VF_flag(complete)