The function call type(c, Range(a, b)) returns true if  and . That is, the type Range( a, b ) represents the open interval (a,b) of the real line.

The endpoints a and b of the interval must be real constants, or the left endpoint a may be of type neg_infinity and the right endpoint b may be of type pos_infinity.

Note that neither a nor b is of type Range( a, b ).