For each of the following predicates:

$$ describe the relation that it defines $($i$.$e$.$ describe when the predicate succeeds$),$

$$ show the input parameters, if any.

$($d$)$ d$([],[]).$

d$([$X$|$L$],$R$)$:$-$ d$($L$,$T$),$ R$=[$X$|[$X$|$T$]].$