[Haskell-cafe] Predicates in data types

Hello, I'm a beginner in Haskell, so forgive me if this is a basic question, but I'd like to know if it's possible to have a predicate as part of a data type, so that when the data type is created, it can only be done if it satisfies the predicate else a type error is thrown. For instance, a matrix with integer elements could be modelled as [[Int]], given the restrictions that - it must have at least one column and one row (so there must be at least one list), and - every list must have the same length so that when a matrix is created, the type system wont allow it if the predicates aren't met. Thanks, Navid