I'm not asking specifically about vectors, that's just a common example of a dependent type. To take another example from the documentation, can you express a t

I'm not asking specifically about vectors, that's just a common example of a dependent type. To take another example from the documentation, can you express a type like type digits = RegexString (Regex "^[0-9]+$") where all values of type digits are strings containing only digits? Then let s1 : digits = "1234" would typecheck but let s2 : digits = "abc" would not? That would be very surprising given the F# type system.