If x and y are sets, then there exists a set which contains x and y as elements.

A formula F(x) that contains exactly one free variable x is called a statement form or class-sign.

If X is locally connected, then, as above, is a clopen set containing x, so and thus .

In this instance, the center itself might be represented as a Point record containing x and y coordinates.

Once we begin to define "smaller" sets containing x, we tend to approximate x to a greater degree of accuracy.

For each point x in an open set U, there is a base element containing x and contained in U.

It does not contain k, w, x, or y even though these letters might be found in some foreign words.

The spillway contains ten-50 x 45 ft. tainter gates that help regulate the reservoir level along with controlling flooding.

Here the direct limit is indexed over all the open sets containing x, with order relation induced by inclusion ( , if ).

Then, among the vertices of "O", exactly vertices correspond to sets that contain "x".