I'm hyp cos, and \(ch(x)=\frac{e^x+e^{-x}}{2}\). If you hang a rope, it looks like the image of y=ch(x).

## Have a look at my stuff

R function series:

- Basic R function
- Brace notation
- Linear array notation
- Dimensional array notation
- Nested array notation
- Hyper nested array notation

Array notation - another work based on the idea of R function

- comparison to ordinal collapsing function (page 1 2 3)
- comparison to Taranovsky's notation
- LAN numbers (on the wikia)
- exAN numbers (on the wikia)

Dropping hydra - a simplified variant of DAN or R function

Second generation dropping notation - The third attempt of second generation Array notation. Array is actually over-complicated but improves nothing from hydra-based notation. Since it definitely doesn't follow the syntax from first generation, I could make it a hydra notation instead of an array notation. It contains this only part:

But it still fails.

Comparisons between different systems of Taranovsky's ordinal notation

## Not my stuff, just category something

List of perfect powers up to \(10^7\)

A list of links to Saibian's ExE googologisms