G.f. method
Defines a new type that represents a subset of the class <integer>.
integers
singleton(<integer>)
min:$minimum-integer.
max:The upper bound of the range. The default is $maximum-integer
limited integer-class #key min max => limited-type
The integer-class argument is the class <integer>, and all other arguments are instances of <integer>. The range of <integer> is bounded by default.