Authentic Science Fiction Monthly No. 48 — page 94: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

AUTHENTIC SCIENCE FICTION Sometimes this condition is reversed, and then we have a many-one relation. “ Sub- ject of the Queen,” “ Crater of the Moon” are both examples of many-one rela- tions because there may be many subjects or craters, while there is only one Queen or Moon. We still have one on one side and many on the other, but they are on different sides now. A fourth and obvious type of relation is the many-many. In such relations, there may. be many terms on one side and many terms on the other side. “Citizens of European countries,’ ‘“‘ Masses of the planets” are examples of many-many relations. Now, since in_ previous articles in this series I have given you the orthodox sym- bolism used by professional logicians, you might as well have the complete picture by including relational sym- bolism—remembering all the time, of course, that sym- bolism is merely shorthand, a 93 quick way of writing some- thing that would be cumber- some in words. Never be afraid of any kind of sym- bolism—no more than you are afraid of other contrac- tions such as etc., i1.€., €.g., and so on. Once you know what the symbols mean it’s as simple as pi! A relation, any relation is represented by R. It could hardly be simpler, could it? The terms between which a relation holds are designated by italic letters from the end of the Roman alphabet— x, y, z. Thus, a relation such as “John loves Mary” would be symbolised simply by xRy. That’s all there is to it, but it makes for very convenient handling. For example, we can ex- press our classifications of relations in the following manner : A relation is symmetrical when, if xRy then yRz. A relation is asymmetrical when, if xRy then not yRx. A rela- tion is non-symmetrical when, comicbooks.com