Is that a Common Lisp thing or something that predates the ANSI standard? SBCL doesn't like that syntax: * 10_000 debugger invoked on a UNBOUND-VARIABL

Is that a Common Lisp thing or something that predates the ANSI standard? SBCL doesn't like that syntax: * 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.htm#possiblesyntaxtypes http://www.lispworks.com/documentation/HyperSpec/Body/02_ad.... http://www.lispworks.com/documentation/HyperSpec/Body/02_adb.htm#constituenttraitsofstdchars http://www.lispworks.com/documentation/HyperSpec/Body/02_adb...