$R=(A,B,C,G,H,I)$

$AC$

$CGH$

$CGI$

$BH$

$(AG{)}^{+}$

result $=AG$

result and $AB$

result $=$ABCGH

and CGsubeAGBC $)$

result $=$ABCGHI

and CGsubeAGBCH $)$

Is AG a candidate key?

Is AG a super key?

Does $AGR?==$ Is $(AG{)}^{+}$supeR

Is any subset of $AG$ a superkey?

Does $AR?==$ Is $(A{)}^{+}$supeR

Does $GR?==$ Is $(G{)}^{+}$supeR

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