simple-string, string, vector, simple-array, array, sequence, t
A simple string is a specialized one-dimensional
simple array whose elements are of type character or a subtype of type character.
When used as a type specifier for object creation,
simple-string means (simple-array character (size)).
Abbreviating.
(simple-string{[size]})
This denotes the union of all types
(simple-array c (size)) for all subtypes c of
character; that is, the set of simple strings of size size.