$1.\{AlongrightarrowBC,$CDlongrightarrowinF,Blongrightarrowin$\}$

Show that $FD,ADF$ holds for $R$

$=>CD$inF

By de composition

$CDlon\frac{?}{?}$& $CDF$

$=>$AlongrightarrowBC

By decomposition

$AB,$&$,$AlongrightarrowC

:$\text{'}AC$ & $CPF$ By psendo transitivity

$AOF$

$2*ABC$

$ECF$

$CDEF$

$BE$

compute the closure $(AB)+$ of the set

of attribute as $A{B}^{\text{'}}.$