Why am I getting all the pizzas(relational algebra) and my joins messing up?

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This is the database I am using for my queries

http://ift.tt/1nLvV0C

the syntax for writing out relational algebra queries is based off http://ift.tt/1pVStR2 .

My query is to "Find all pizzas eaten by at least one female over the age of 20." this is what I have so far

\project_{name,pizza}(
Person \join_{gender='female' and age>20} Eats

) I think I have the right logic here. I am joining two relations and only keeping the rows where gender is female and age is > 20.

The result of my query(against the correct query). I don't think this is a syntax issue. In the Eats relation, Fay only eats mushroom. I don't understand why she is paired with every pizza combination

is

asked 23 secs ago

committedandroider

573

Why am I getting all the pizzas(relational algebra) and my joins messing up?