Definition:Termial/Real Numbers
Jump to navigation
Jump to search
Definition
Let $x \in \R$ be a real number.
The termial of $x$ is denoted $x?$ and defined as:
- $x? = \dfrac {x \paren {x + 1} } 2$
Also see
Historical Note
The termial was invented by Donald E. Knuth in his The Art of Computer Programming.
It was devised as an analogy of the factorial, so as to illustrate the extension of the latter to the real numbers.
Sources
- 1997: Donald E. Knuth: The Art of Computer Programming: Volume 1: Fundamental Algorithms (3rd ed.) ... (previous) ... (next): $\S 1.2.5$: Permutations and Factorials: $(9)$