Common errors/resulting messages in common lisp (gcl specifically): 1. You put the #! line in a file then try to load it, i.e. (load "filename.cl") Error message: "BROKEN AT LOAD" 2. You're missing a ) somewhere Error message: "END-OF-FILE :STREAM " 3. You're missing a " No error message, it just hangs waiting to find another " 4. You forget the ' in front of a data list or you put ( ) around a data value, e.g. (3) Error message: TYPE-ERROR :DATUM the front element of the list :EXPECTED-TYPE FUNCTION 5. You pass an incorrect data type to an operator or function Error message: TYPE-ERROR :DATUM the value you passed :EXPECTED-TYPE the kind of data it expected 6. You use an undeclared variable (or undeclared in the current scope) Error message: UNBOUND-VARIABLE :NAME your variable name 7. You use an undeclared function (or undeclared in the current scope) Error message: UNBOUND-FUNCTION :NAME your function name or: UNDEFINED-FUNCTION :NAME your function name 8. You call a function with the incorrect number of arguments Error message: PROGRAM ERROR function name REQUIRES more/less THAN n ARGUMENTS where n is the number of arguments you actually passed 9. You have infinite recursion Error message: Frame Stack overflow