The three classical centres of a triangle — circumcenter, incenter, and centroid — each computed by the type system from the same three vertices. No coordinates guessed.
A 3-4-5 right triangle with coloured squares on each side. Area labels via dot-access to each square's centre. The classic visual proof of a² + b² = c².
Two function curves with their intersection points found numerically and used as integral bounds. The crossings are referenceable as points — their x coordinates feed directly into the integral.
The diff type computes the derivative numerically at a given x and optionally draws the tangent line. The slope is readable via dot access — pipe it into a label to display the value.