Magnitudes are totally orderable objects.  Users are only required to
implement < and =.
| <mag> | (<any>) | C | 
| < | (x|<mag> y|<mag> => <log>) | G | 
|  | returns iff x is less than y. |  | 
| > | (x|<mag> y|<mag> => <log>) | G | 
|  | ==  (not (or (< x y) (= x y))). |  | 
| <= | (x|<mag> y|<mag> => <log>) | G | 
|  | ==  (or (< x y) (= x y)). |  | 
| >= | (x|<mag> y|<mag> => <log>) | G | 
|  | ==  (not (< x y)). |  | 
| min | (x|<mag> y|<mag> => <mag>) | G | 
|  | returns the smallest of x and y. |  | 
| max | (x|<mag> y|<mag> => <mag>) | G | 
|  | returns the largest of x and y. |  | 
|  |