--- /dev/null
+import "JavaBuiltin" as Java\r
+\r
+importJava "org.simantics.scl.runtime.Lists" where\r
+ foldl :: (a -> b -> a) -> a -> [b] -> a\r
+\r
+class Additive a where\r
+ zero :: a\r
+ (+) :: a -> a -> a \r
+ \r
+ sum :: [a] -> a\r
+ sum = foldl (+) zero \r
+ \r
+instance (Additive a, Additive b, Additive c) => Additive (a, b, c) where\r
+ zero = (zero, zero, zero)\r
+ (a0, b0, c0) + (a1, b1, c1) = (a0+a1, b0+b1, c0+c1)\r
+ \r
+main = "OK"\r
+--\r
+OK
\ No newline at end of file