Recursion newLISP无效函数

我有一个家庭作业，我们需要用newLISP编写一些函数。我遇到了一个问题，所以我举了一个例子，看看是否有人能帮我解决这个问题

问题是递归函数结束后，它返回一个

ERR:invalid function:

error。无论我调用的

函数是什么，都会发生这种情况

例如，我创建了一个递归函数，它递减一个数字直到达到0。代码如下：

 (define (decrement num)
   (if (> num 0)
     (
       (println num)
       (decrement (- num 1))
     ) 
     
     (
       (println "done")
     )
   ) 
 )

每当我运行此函数时，从数字10开始，输出如下所示：

> (decrement 10)
10
9
8
7
6
5
4
3
2
1
done
ERR: invalid function : ((println "done"))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement 10)

(define (decrement num)
   (if (> num 0)
      (begin
        (println num)
        (decrement (- num 1))
      )
      (println "done")
   ) 
 )

我无法理解为什么返回无效函数错误。我对newLISP知之甚少，所以这可能是一个简单的问题

谢谢
 在Lisp中，不能使用任意括号将内容分组。所以你应该这样做：

> (decrement 10)
10
9
8
7
6
5
4
3
2
1
done
ERR: invalid function : ((println "done"))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement (- num 1))
called from user function (decrement 10)

(define (decrement num)
   (if (> num 0)
      (begin
        (println num)
        (decrement (- num 1))
      )
      (println "done")
   ) 
 )

谢谢你，这解决了我的问题，帮助我明白我做错了什么！