Or you could be obnoxious and use the syntax that made its way into the EcmaScript standard: 10_000
* 10_000
debugger invoked on a UNBOUND-VARIABLE: The variable |10_000| is unbound.
According to the Common Lisp HyperSpec, "_" is an alphabetic constituent character:http://www.lispworks.com/documentation/HyperSpec/Body/02_ad....
http://www.lispworks.com/documentation/HyperSpec/Body/02_adb...