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How to find which individuals likes every topics they study in relational algebra?

 
Antoine Compagnie
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Posts: 34
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Hi!

I'm new to studying relational algebra and I have an exercise wich makes me stumbling, maybe owing to its newness.
Here are three database:

Likes(Person,Topic)
Studies(PersonTopic)
Hates(Person,Topic)

How to find which individuals likes every topics they study in relational algebra?

My attempt:

π<sub>Person</sub>(π<sub>Topic</sub>(Study)∩π<sub>Topic</sub>(Like))

But I think its wrong as far as the following question is "How to find which individuals study every topics they like in relational algebra"?

PS: Do you know how to write in proper mathematic style? It seems that Latex isn't implemented over there...
 
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