Fix tf strings for printing

src/lib.rs

@@ -207,7 +207,7 @@ mod pole_position_app {
         fn parameter_sliders(&mut self, ui: &mut Ui) {
             match self.order {
                 Order::First => {
-                    ui.heading("G(s) = 1/(sT - 1)");
+                    ui.heading("G(s) = 1/(sT + 1)");
                     ui.add(
                         egui::Slider::new(&mut self.fo.T, self.fo.T_lower..=self.fo.T_upper)
                             .text("T")