Welcome to Scala version 2.10.3 (Java HotSpot(TM) 64-Bit Server VM, Java 1.7.0_45).
Type in expressions to have them evaluated.
Type :help for more information.

scala> def ints(a: Any) = a match { case l: List[Int] => true; case _ => false }
<console>:7: warning: non-variable type argument Int in type pattern List[Int] is unchecked since it is eliminated by erasure
       def ints(a: Any) = a match { case l: List[Int] => true; case _ => false }
                                            ^
ints: (a: Any)Boolean

scala> ints(List("1"))
res0: Boolean = true

scala> type Ints = List[Int]
defined type alias Ints

scala> def ints2(a: Any) = a match { case l: Ints => true; case _ => false }
ints2: (a: Any)Boolean

scala> ints2(List("1"))
res1: Boolean = true

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