位い相そう幾き何か学がく

noun

topology

The mathematical study of properties preserved under continuous deformations, such as stretching and bending, but not tearing or gluing.

• 位い相そう幾き何か学がくでは、コーヒーカップとドーナツは同おなじ形かたちとみなされる。

  In topology, a coffee cup and a doughnut are considered the same shape.