diff --git a/examples/Makefile.am b/examples/Makefile.am
index 34353ed..32daf83 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -15,15 +15,25 @@ endif
 endif
 
 noinst_PROGRAMS =           \
-    exMathInterpreter          \
-    exCompiledDoubleFunction
-
-exMathInterpreter_SOURCES        = exMathInterpreter.cpp
-exMathInterpreter_CFLAGS         = -g -O2
-exMathInterpreter_LDFLAGS        = -L../latan/.libs -llatan
+    exCompiledDoubleFunction\
+    exMat                   \
+    exMathInterpreter       \
+    exPlot
 
 exCompiledDoubleFunction_SOURCES = exCompiledDoubleFunction.cpp
 exCompiledDoubleFunction_CFLAGS  = -g -O2
 exCompiledDoubleFunction_LDFLAGS = -L../latan/.libs -llatan
 
+exMat_SOURCES                    = exMat.cpp
+exMat_CFLAGS                     = -g -O2
+exMat_LDFLAGS                    = -L../latan/.libs -llatan
+
+exMathInterpreter_SOURCES        = exMathInterpreter.cpp
+exMathInterpreter_CFLAGS         = -g -O2
+exMathInterpreter_LDFLAGS        = -L../latan/.libs -llatan
+
+exPlot_SOURCES                   = exPlot.cpp
+exPlot_CFLAGS                    = -g -O2
+exPlot_LDFLAGS                   = -L../latan/.libs -llatan
+
 ACLOCAL_AMFLAGS = -I .buildutils/m4
diff --git a/examples/exMat.cpp b/examples/exMat.cpp
new file mode 100644
index 0000000..c347360
--- /dev/null
+++ b/examples/exMat.cpp
@@ -0,0 +1,30 @@
+#include <iostream>
+#include <latan/Io.hpp>
+#include <latan/Mat.hpp>
+
+using namespace std;
+using namespace Latan;
+
+int main(void)
+{
+    AsciiFile F;
+    DMat A,B;
+    const string fileName = "exMat.dat";
+    
+    // read
+    cout << "-- reading " << fileName << "..." << endl;
+    F.open(fileName, File::Mode::read);
+    A = F.read<DMat>("A");
+    B = F.read<DMat>("B");
+    cout << "A=\n"   << A   << '\n' << endl;
+    cout << "B=\n"   << B   << '\n' << endl;
+    cout << "A*B=\n" << A*B << '\n' << endl;
+    F.close();
+    
+    // write
+    cout << "-- saving A*B..." << endl;
+    F.open(fileName, File::Mode::append);
+    F.save((A*B).eval(), "AB");
+    
+    return EXIT_SUCCESS;
+}
diff --git a/examples/exMathInterpreter.cpp b/examples/exMathInterpreter.cpp
index 42df050..aaf5417 100644
--- a/examples/exMathInterpreter.cpp
+++ b/examples/exMathInterpreter.cpp
@@ -41,35 +41,3 @@ int main(int argc, char* argv[])
     
     return EXIT_SUCCESS;
 }
-
-/*int main(void)
-{
-    ASCIIFile F;
-    DMat A,B;
-    
-    F.Open("foo.boot",FileMode::Read);
-    A = F.Read<DMat>("bla");
-    B = F.Read<DMat>("bli");
-    cout << A << endl;
-    cout << B << endl;
-    cout << A*B << endl;
-
-    return EXIT_SUCCESS;
-}*/
-
-/*
-int main(void)
-{
-    DMat m(2,2);
-    
-    m(0,6) = 3;
-    m(1,0) = 2.5;
-    m(0,1) = -1;
-    m(1,1) = m(1,0) + m(0,1);
-    cout << "Here is the matrix m:\n" << m << endl;
-    DVec v(2);
-    v(0) = 4;
-    v(1) = v(0) - 1;
-    cout << "Here is the vector v:\n" << v << endl;
-}
-*/
diff --git a/examples/exPlot.cpp b/examples/exPlot.cpp
new file mode 100644
index 0000000..cd87c3d
--- /dev/null
+++ b/examples/exPlot.cpp
@@ -0,0 +1,16 @@
+#include <iostream>
+#include <latan/Plot.hpp>
+
+using namespace std;
+using namespace Latan;
+
+int main(void)
+{
+    Plot p;
+    
+    p << PlotCommand("x**2") << PlotCommand("x**3") << PlotCommand("x**4");
+    cout << p << endl;
+    p.display();
+    
+    return EXIT_SUCCESS;
+}
diff --git a/latan/MathInterpreter.hpp b/latan/MathInterpreter.hpp
index 88f06ea..8ba26b3 100644
--- a/latan/MathInterpreter.hpp
+++ b/latan/MathInterpreter.hpp
@@ -34,7 +34,7 @@
 BEGIN_NAMESPACE
 
 /******************************************************************************
- *                              Parser classes                                *
+ *                            Expression node class                           *
  ******************************************************************************/
 class MathNode
 {
@@ -191,7 +191,7 @@ DECL_OP(Div);
 DECL_OP(Pow);
 
 /******************************************************************************
- *                               Compiler class                               *
+ *                            Interpreter class                               *
  ******************************************************************************/
 class MathInterpreter
 {
diff --git a/latan/ParserState.hpp b/latan/ParserState.hpp
index 7f687d0..f5b21d9 100644
--- a/latan/ParserState.hpp
+++ b/latan/ParserState.hpp
@@ -40,10 +40,10 @@ private:
     virtual void initScanner(void)    = 0;
     virtual void destroyScanner(void) = 0;
 public:
-    DataObj*      data;
-    void*         scanner;
-    std::istream* stream;
-    std::string*  streamName;
+    DataObj       *data;
+    void          *scanner;
+    std::istream  *stream;
+    std::string   *streamName;
     
 };