Re: On Formal IS-A definition

On May 8, 7:11 am, David BL <davi..._at_iinet.net.au> wrote:
> Values are immutable.  Variables accessed by imperative programs are
> usually mutable.  Sets are values.  If a set contained a variable then
> it wouldn't be immutable.

We can generalize values and variables to elements of domains, where a value is any element of a domain while a variable is an element of a domain for which a homomorphism to another domain is defined. Assigning to a variable would reduce to modification of the homomorphism, so sets containing variables would not be modified by assignment to a variable. Received on Sat May 08 2010 - 20:34:49 CEST