Common Lisp Variable addFraction is unbound

Question

为什么说变量addFraction是Unbound？

(defun addFraction (N1 D1 N2 D2)
(format t "~d ~d"
(+ (+ (lcm D1 D2) N1) (+ (lcm D1 D2) N2))
(lcm D1 D2)))

当我运行代码时，上面写着：

#<THREAD "main thread" RUNNING {10010B0523}>:
The variable ADDFRACTION is unbound.
Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.
restarts (invokable by number or by possibly-abbreviated name):
0: [CONTINUE   ] Retry using ADDFRACTION.
1: [USE-VALUE  ] Use specified value.
2: [STORE-VALUE] Set specified value and use it.
3: [ABORT      ] Exit debugger, returning to top level.
(SB-INT:SIMPLE-EVAL-IN-LEXENV ADDFRACTION #<NULL-LEXENV>)
0]

Answer 1

我的坏！

当我调用函数时，我键入了

addFunction (1 2 1 4)

代替

(addFunction 1 2 1 4)