--- a/handouts/ho01.tex	Sat Dec 14 17:57:43 2019 +0000
+++ b/handouts/ho01.tex	Fri Jan 24 20:51:19 2020 +0000
@@ -85,6 +85,10 @@
 %You might also be surprised what
 %constraints programming languages impose about numbers: for example
 %123 in JSON is OK, but 0123 is not.
+%
+% The regex for JASON numbers is
+%
+% -?(0|[1-9][0-9]*)(\.[0-9]+)?([eE][+-]?[0-9]+)?
 
 Often we also face the problem that we are given a string, for example
 some user input, and we want to know whether it matches a particular