Show Within a Show, if the X is a dream, the subtrope in question is a Dream Within a Dream. May also extend further to X-within-X-within-X, etc. Often used as a form of Mind Screw.
- Parodied in the above XKCD alt-text.
- Seen in many math-related fields, such as computer science, which has nested if-statements or nested do-loops to control for several conditions, and math itself, wherein a "second derivative" is basically a derivative of a derivative, a "third derivative" is basically a derivative of THAT, etc...
- Also, fractals
- This meme.
- All examples of Show Within a Show and Dream Within a Dream double as examples of this.
Hello, Unknown Troper. You'll need to get known to lend a hand here.