The function
which gives the smallest Integer , shown as the thick curve in the above plot.
Schroeder (1991) calls the ceiling function symbols the ``Gallows'' because of the similarity in appearance to the
structure used for hangings. The name and symbol for the ceiling function were coined by K. E. Iverson (Graham *et al. *1990).
It can be implemented as `ceil(x)=-int(-x)`, where `int(x)` is the Integer Part
of .

**References**

Graham, R. L.; Knuth, D. E.; and Patashnik, O. ``Integer Functions.'' Ch. 3 in
*Concrete Mathematics: A Foundation for Computer Science.* Reading, MA: Addison-Wesley, pp. 67-101, 1990.

Iverson, K. E. *A Programming Language.* New York: Wiley, p. 12, 1962.

Schroeder, M. *Fractals, Chaos, Power Laws: Minutes from an Infinite Paradise.* New York: W. H. Freeman, p. 57, 1991.

© 1996-9

1999-05-26