                     Draw.drawCurve(context, curve: curve)
                     Draw.setColor(context, color: Draw.red)
                     for t in stride(from: 0, through: 1, by: 0.1) {
-                        let pt = curve.compute(BKFloat(t));
-                        let dv = curve.derivative(BKFloat(t));
-                        Draw.drawLine(context, from: pt, to: pt + dv );
+                        let pt = curve.compute(BKFloat(t))
+                        let dv = curve.derivative(BKFloat(t))
+                        Draw.drawLine(context, from: pt, to: pt + dv )
                     }
 })
 let demo7 = Demo(title: ".normal(t)",

                    let c = curve.split(from: 0.25, to: 0.75)
                    Draw.setColor(context, color: Draw.red)
                    Draw.drawCurve(context, curve: c)
                    Draw.drawCircle(context, center: curve.compute(0.25), radius: 3);
                    Draw.drawCircle(context, center: curve.compute(0.75), radius: 3);
})
let demo9 = Demo(title: ".extrema()",
                 quadraticControlPoints: quadraticControlPoints,

                    Draw.drawCurve(context, curve: curve)
                    Draw.setColor(context, color: Draw.red)
                    let hull = curve.hull(0.5)
                    Draw.drawHull(context, hull: hull)
                    Draw.drawCircle(context, center: hull[hull.count-1], radius: 5)
})
let demo12 = Demo(title: ".project(point)",
                  quadraticControlPoints: quadraticControlPoints,
