I have this code :

```
(ns triangle)
(defn have-valid-lengths?
"two sides of the triangle must be more then the 3th side"
[s1 s2 s3]
(or (> (+ s1 s2) s3) (> (+ s1 s3) s2) (> (+ s2 s3) s1)))
(defn no-zero-sides?
" a triangle does not have a side with the length of zero"
[s1 s2 s3]
(not (zero? s1 s2 s3)))
(defn is-valid?
" a triangle is valid when no sides have a length of zero and the sides are all valid"
[s1 s2 s3]
(and (no-zero-sides?(s1 s2 s3)) (have-valid-lengths?(s1 s2 s3))))
(defn equilateral?
"a equilateral is a triangle which sides have the same length and is valid"
[s1 s2 s3]
(and (== s1 s2) (== s2 s3) (== s1 s3) (is-valid? s1 s2 s3) ))
(defn isosceles? [] ;; <- arglist goes here
;; your code goes here
)
(defn scalene? [] ;; <- arglist goes here
;; your code goes here
)
```

but now I see this error message :

```
java.lang.ClassCastException: java.lang.Long cannot be cast to clojure.lang.IFn
```

Can someone help me figure out what I did wrong ?