It seems to me Kroch’s and Santorini’s rendition of this function:
| (1) |
|
|
[[ invite ]] = { |
Chris |
→ |
( Andrew |
→ |
T ) , |
| |
David |
→ |
( Andrew |
→ |
T ) , |
| |
Eddie |
→ |
( Andrew |
→ |
F ) , |
| |
Chris |
→ |
( Brian |
→ |
F ) , |
| |
David |
→ |
( Brian |
→ |
F ) , |
| |
Eddie |
→ |
( Brian |
→ |
T ) } |
is off, since in a function the first entity in a given ordered pair can be mapped to one and only one entity.
Shouldn’t the function be represented this way:
| (2) |
|
|
[[ invite ]] = { |
Chris |
→ |
{ ( Andrew |
→ |
T ) , |
( Brian |
→ |
F ) , |
. . . } |
| |
David |
→ |
( Andrew |
→ |
T ) , |
( Brian |
→ |
F ) , |
. . . } |
| |
Eddie |
→ |
( Andrew |
→ |
F ) , |
( Brian |
→ |
T ) , |
. . . } |
| } |
|
|
|
|
|
|
|
|
|
?
Or am I missing something obvious?
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About Cliff Wirt
I created this blog as a means of getting my thoughts in order about whatever topics I am interested in at the moment. These are always topics for which getting my thoughts in order is a bit of a challenge, so I expect most of my attempts to fail. (I keep trying, though.) I am not responsible for any brain damage the reader may incur from these posts. They (intentional use of 'they' as the epicene singular pronoun) are hereby warned. . . . Who am I? I am a banking DBA with various and sundry interests, including art, poetry, philosophy, music, languages, relational algebra, database administration, and blueberries. Don't forget the blueberries. Some of these interests tie in in surprising though usually tangential ways with database theory. Even the blueberries. I have published one article in a Philosophy Journal, and I have one painting in a corporate collection (housed in what used to be the Amoco building in Chicago). According to 23andMe, my paternal haplogroup is I2 (40% of the male population of Sardinia has this haplogroup, though I believe that my particular variation originated further north in the Baltic area. The Basques are apparently close cousins.), my maternal is H5. The Neanderthal percentage of my ancestry is 3%. (Let no one impugn my knuckle-dragging bonafides!) My most famous ancestor is William Wirt (from whom I get my last name, though possibly not my Y chromosome), who defended the rights of the Cherokees before the Supreme Court, and ran for President in 1832, carrying one state. My homepage is at http://www.cliff-engel-wirt.com. My FaceBook page is at https://www.facebook.com/cliffengelwirt. My LinkedIn page is at https://www.linkedin.com/profile/view?id=4298877&trk=nav_responsive_tab_profile_pic.
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