Not enough/too many arguments for the type T

Some built-in types expect to be given one or more types as arguments (for example, List and Set both expect one argument; Map expects two). You can also define your own types that expect arguments. These error messages show up when you have given the wrong number of arguments to a type. For example:

Disco> t : List
Error: not enough arguments for the type 'List'.
Disco> t : List(N,Q)
Error: too many arguments for the type 'List'.
Disco> type MyType(a,b,c) = List(a) * Set(b) * List(c)
Disco> q : MyType(Char,Bool)
Error: not enough arguments for the type 'MyType'.