Before reading this article, read 'Glome in colors'.
Suppose a three-dimensional space which is bounded and path-connected. Let the space contain holes.
Let f and g be continuous functions taking this space as a domain.
f(x,y,z) is equal to g(x,y,z) at the boundary of the space and is different at the other points in the space.
By assigning these values to each point in the space, we get a four-dimensional surface.
It can be called a luffa.