doc/concepts.tex: Apparently `aging' is predominantly a US spelling.

diff --git a/doc/concepts.tex b/doc/concepts.tex
index c4bcf61..0533a68 100644 (file)
--- a/doc/concepts.tex
+++ b/doc/concepts.tex
@@ -537,7 +537,7 @@ Keyword arguments can be provided in three ways.
 \end{enumerate}
 
 Perhaps surprisingly, keyword arguments have a relatively small performance
-impact.  On the author's aging laptop, a call to a simple function, passing
+impact.  On the author's ageing laptop, a call to a simple function, passing
 two out of three keyword arguments, takes about 30 cycles longer than calling
 a standard function which just takes integer arguments.  On the other hand,
 quite a lot of code is involved in decoding keyword arguments, so code size