The ORM Foundation

 Hi Victor,

I think there's a question I can ask of you that I trust will lend itself to a simple answer (if it's a trick question,or has transcendental implications, I sure don't see it that way).  In the image you attached to the post, it looks like the sample population table entries are not sufficient to indicate the choice of constraints used.  Beside the [ a ][ b ], [ a ][ c ], I think you'd need [ d ][ b ] (at least) to complete the constraints for that Fact Type.  Is that an oversight, a truncation of the image, or something else?

BRN..

Hi Brian,

Thank you for participating. If you want to ask questions about isomorphism in general, you might like to start a different thread. Answers to my questions may answer yours.

Is there an echo in here?

An answer fitting to the quality of that question...

I used to have a wheelbarrow like that...but the wheels fell off! It was just the darndest thing...
OR
'no, neither, you need to read more books'. None of which are probably the answer you wee looking for. I am sorry, I said I don't want to discuss it any further.

For further research, see p. 'A-4' of DR Halpin's thesis, and ponder "1. When you perform 45432454509 * 13452356727 on paper in pencil, do you consider your 'working' in the answer, or do you consider 611173585038267632043 (the answer)? The answer to that is the answer to your question."

Best regds
Victor

Hi Brian,

The example is quoted almost verbatim from Dr Halpin's thesis (See Proof 1, p. 'A-4' of Dr Halpin's thesis).

Perhaps you may dignify this forum by adding commentary on your comments "In the image you attached to the post, it looks like the sample population table entries are not sufficient to indicate the choice of constraints used.  Beside the [ a ][ b ], [ a ][ c ], I think you'd need [ d ][ b ] (at least) to complete the constraints for that Fact Type.  Is that an oversight, a truncation of the image, or something else?"

Or is it that we reserve dignity exclusively for ourselves, and not others?

There's not, but this forum is available to a potential audience of billions of people. Forgive me if I chose to leave my post with "Oh...that's cool.... Thank you Dr, I think that opens up some fairly interesting possibilities in ORM research.".

Best regds
Victor