                     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)",

                            Draw.drawCurve(context, curve: c)
                        }
                        for i in stride(from: -30, through: 30, by: 10) {
                            Draw.drawCurve(context, curve: reduced[(reduced.count/2)].curve.scale(distance: BKFloat(i)));
                        }
                    }
                    else {

                  drawFunction: {(context: CGContext, demoState: DemoState) in
                    let curve = demoState.curve!
                    Draw.drawSkeleton(context, curve: curve)
                    let arcs = curve.arcs()
                    Draw.setColor(context, color: Draw.black)
                    for arc in arcs {
                        Draw.setRandomFill(context, alpha: 0.1)
                        Draw.draw(context, arc: arc)
                    }
})
let demo16 = Demo(title: ".scale(d)",
