We want to explore here, how many topological types the letters in our alphabet have. 1) The numbers 0, 4, 6, 9 are topologically equivalent. 2) The numbers 1, 2, 3, 5, 7 are topologically equivalent.

Which shapes are topologically equivalent?

A circle is topologically equivalent to an ellipse (into which it can be deformed by stretching) and a sphere is equivalent to an ellipsoid.

Which letters are homeomorphic?

For example, the letters C, I and L are homeomorphic such as it is illustrated in Fig. 1. Figure 1. The transformations between the letters C, I and L by stretching and bending show that all are home- omorphic.