Surrogate symbol for superscript and exponentiation
In mathematics, the caret can signify exponentiation (3^5 for 35), where the usual superscript is not readily usable (as on some graphing calculators). The caret is also now used to indicate a superscript in TeX typesetting. As Isaac Asimov described it in his 1974 "Skewered!" essay (on Skewes' number), "I make the exponent a figure of normal size and it is as though it is being held up by a lever, and its added weight when its size grows bends the lever down."[13] The use of the caret for exponentiation can be traced back to ALGOL 60,[citation needed] which expressed the exponentiation operator as an upward-pointing arrow, intended to evoke the superscript notation common in mathematics. The upward-pointing arrow is now used as a form of iterated exponentiation in Knuth's up-arrow notation.
