Art.  2055. A guaranty is not presumed; it must be express and cannot extend to more than what is stipulated therein.

If it be simple or indefinite, it shall compromise not only the principal  obligation,  but  also  all  its  accessories,  including the  judicial  costs,  provided  with  respect  to  the  latter,  that the  guarantor  shall  only  be  liable  for  those  costs  incurred after he has been judicially required to pay. (1827a)

>     Requires  the  expression  of  consent  on  the  part  of  the guarantor to be bound
>     It  cannot  be  presumed  because  of  the  existence  of  a contract or principal obligation
>     Why  this  rule?    The  law  wants  not  only  that  there  be assurance that the guarantor has the true intention to bind himself  but  also  to  make  certain  that  on  making  it,  he proceeded with consciousness of what he was doing