23.02.2014 Views

Shape

Shape

Shape

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

221 ‘‘Nor Do Lineaments Have Anything to Do with Material’’<br />

section—and so will only give a brief outline. In fact, I’ll just do adding and subtracting,<br />

as each normally implies the part relation (table 6, facts 1 and 2). The idea is to<br />

insert an algebra of weights—with labels, it’s just the Boolean algebra for sets—in an<br />

algebra of shapes. Points are trivial. The problem is with lines, planes, and solids.<br />

The basic elements in a weighted shape are maximal in the sense that ones of<br />

equal weight are. For a weighted shape A, let A be the shape defined when all of its<br />

weights are stripped away. Let’s suppose A is the weighted shape<br />

Then A is the shape<br />

And for planes, if A is<br />

then A is<br />

The sum of two weighted shapes A and B in an algebra W ij is formed by dividing<br />

the basic elements in A and B into separate pieces to assign weights. These new basic<br />

elements are distinguished according to whether they contribute to the differences<br />

A B or B A , or to the product A B . These parts are distinct and separate from<br />

one another, and they totally exhaust the sum A þ B <br />

The weights assigned to the basic elements that contribute to the differences are taken<br />

directly from A and B, while the weights assigned to the basic elements that contribute<br />

to the product are defined in unions. This process is easy to illustrate for lines

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!