void compile()
{
   TCanvas *c1 = new TCanvas("c1");
   c1->Range(0, 0, 1, 1);
   TPaveLabel *ptc = new TPaveLabel(0.02, 0.42, 0.2, 0.58, "Compile");
   ptc->SetTextSize(0.40);
   ptc->SetFillColor(32);
   ptc->Draw();
   TPaveText *psub = new TPaveText(0.28, 0.4, 0.65, 0.6);
   psub->Draw();
   TText *t2 = psub->AddText("Substitute some operators");
   TText *t3 = psub->AddText("to C++ style");
   TPaveLabel *panal = new TPaveLabel(0.73, 0.42, 0.98, 0.58, "Analyze");
   panal->SetTextSize(0.40);
   panal->SetFillColor(42);
   panal->Draw();
   TArrow *ar1 = new TArrow(0.2, 0.5, 0.27, 0.5, 0.02, "|>");
   ar1->SetLineWidth(6);
   ar1->SetLineColor(4);
   ar1->Draw();
   TArrow *ar2 = new TArrow(0.65, 0.5, 0.72, 0.5, 0.02, "|>");
   ar2->SetLineWidth(6);
   ar2->SetLineColor(4);
   ar2->Draw();
}