EQ in Common Lisp is not for comparison of characters and numbers. Characters and numbers have no identity and may be copied by an implementation. Thus effectively comparing 3 and 3 with EQ can be T or NIL. Same with characters.
The default comparison operator is EQL. EQL also works for characters and numbers.
See: http://www.lispworks.com/documentation/lw51/CLHS/Body/f_eql.htm
The software seams to have various usage of EQ to compare numbers and characters. That can lead to strange runtime behavior.
EQ in Common Lisp is not for comparison of characters and numbers. Characters and numbers have no identity and may be copied by an implementation. Thus effectively comparing 3 and 3 with EQ can be T or NIL. Same with characters.
The default comparison operator is EQL. EQL also works for characters and numbers.
See: http://www.lispworks.com/documentation/lw51/CLHS/Body/f_eql.htm
The software seams to have various usage of EQ to compare numbers and characters. That can lead to strange runtime behavior.