## char-ci<=? - check whether characters are in increasing order, ignoring case

Predicate`char-ci<=?`
Parametersc1 ... cn, n characters
PurposeDetermines whether or not the characters are in increasing order, ignoring case for alphabetic characters.
ProducesA Boolean value: true (`#t` if ci precedes or is equal to ci+1 for all reasonable values of i.
PreconditionsAt least one parameter (verified).
All the c's are characters (verified).
PostconditionsThe result is a Boolean value.
Note
```The ordering of characters may depend on the Scheme implementation.
However, the following are guaranteed: The letters are in
alphabetical order from `#\a` and `#\A`
to `#\z` and `#\Z`;
and the digits are in order from `#\0` to `#\9`.```
Examples
```> (char-ci<=? #\a #\b #\c)
#t
> (char<? #\a #\B #\c)
#f
> (char-ci<=? #\a #\B #\c)
#t
> (char-ci<=? #\a #\b #\B #\c)
#t
> (char-ci<? #\a #\b #\B #\c)
#f
```
```  `char<?`,
`char<=?`,
`char=?`,
`char>?`,
`char>?`,
`char-ci<=?`,
`char-ci<==?`,
`char-ci=?`,
`char-ci<=?`,
`char-ci-ci<=?`,
`char->integer`,
`integer->char`
```

Disclaimer: I usually create these pages on the fly. This means that they are rarely proofread and may contain bad grammar and incorrect details. It also means that I may update them regularly (see the history for more details). Feel free to contact me with any suggestions for changes.

This page was generated by Siteweaver on Thu Feb 22 05:47:40 2001.
This page may be found at `http://www.cs.grinnell.edu/~rebelsky/Courses/CS151/2001S/char-ci-lessequal-p.html`.