Drexel dragonThe Math ForumDonate to the Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.

Math Forum » Discussions » sci.math.* » sci.math.independent

Topic: Imaging temporal Mereotopology
Replies: 0  

Advanced Search

Back to Topic List Back to Topic List  

Posts: 2,665
Registered: 6/29/07
Imaging temporal Mereotopology
Posted: Apr 3, 2013 4:41 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

In my last explanation about sets, one thing that I must mention is
that the size criterion followed in standard set theories is not
clearly motivated by it. There is no clear relationship between the
size of a collection and the ability to have a label (name) for it? We
can change the metaphor of "label" or "name" to that of "image", then
this can be motivated since some collections might be so big that they
cannot be imaged! This would fit most well founded sets and it would
break down with non well foundedness. However there is another line of
imagination that follows Temporal Mereotopology, in which another
primitive is added to part-hood and identity, that is "timed Contact".

Timed contact is a Three place relation symbol, the notation of it is
the following

C(x,y,t) standing for x in contact with y at moment t.

No being in "contact" mean that the object in contact to each other
are disjoint (discrete) i.e. no overlap between them (share no common
part), and that there is no gap between some parts of them. Of course
all of that relative to some moment t, so if x and y are in contact
with each other at t they might not be so at another moment t*.

Axioms for C(x,y,t) are:

Ax.1: C(x,y,t) -> C(y,x,t)
Ax.2: C(x,y,t) & x,y are not atoms ->Exist a,b: a PP x & b PP y &
Ax.3: (For all z. C(x,z,t) <->C(y,z,t)) -> x=y
Ax.4: (Exist t. C(x,y,t)) -> ~ x O y

Now a very important concept is that of a temporal mereotopological

notation: Unit(x,t) read as x is a unit at moment t. The informal idea
is that for x to be compact. This is defined as:

Unit(x,t) iff [~ Exist y. C(x,y,t)] &
[For all q. q PP x -> Exist g. g PP x & C(q,g,t)]

Unitof(x,y,t) read as: x is a unit of y at moment t. This is defined

Unitof(x,y,t) iff Unit(x,t) & x P y

Now we come to add another primitive relation that is "image", the
idea is
that of copying but the difference is that a copy will never break
down into further smaller Unites at any moment t. Also the idea of
this methodology is
guarantee having Images of Units. Of course images of two units might
come into contact with each other at some moment t at then they'd
become a unit and they'd be guaranteed an image!

Ax5: x Image of y -> ~Exist z,t. z PP x & Unit(z,t)
Ax6: x image of y & k image of q -> ~ x O k
Ax.7. Exist t. Unit(x,t) -> Exist m. m image of x & Unit(m,t)

The nice idea is to define Membership after the following relation:

x E y iff Class(y) & Exist z. z P y & z image of x

Class would be defined as the collection of All images of some units.

Now to understand that: lets say we have two unites A,B at some moment
t, then those would be guaranteed to have images A*,A2*,..B1*,
B2* ...that are unites at moment t. Now the collection of All those
images is the set {A,b}.
Now that all unites (at t) of that collections might at another moment
t* gather together and be in contact so that the whole collection
becomes a UNIT at t*, by then it would be guaranteed an image {A,b}* ,
now the collection of all those images would be The set {{A,b}}. And
so on...

This line of imaginary thought that highly simulate temporal
topological properties of existing material in our world, does provide
some motivation for having a size criterion upon sets. Clearly
collections that are so big cannot have all its unites contacting to
form a unit, and accordingly it might not have an image and cannot
become an element of a class, thus would be a PROPER class.
This is a reasonable motivation.

The above line of thought is what I called as: Imaging temporal


Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2014. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.