Part I Obligations arising from contracts: Formation of the contract -- Public promise -- Form of the contract -- Standard terms -- Content of the contract -- Abstract acknowledgement of debt -- Contract interpretation and simulation -- Incomplete contracts -- Revision of the contract (hardship) -- Mistake, fraud and duress -- Unfair exploitation (lesion) -- Agency -- Part II The effect of obligations, performance, non-performance, the effect on third parties: Performance of obligations -- The object of performance -- Performance of the debtor -- Place of performance -- Time of performance -- Proof of performance -- Default of creditor -- Natural obligations -- Non-performance of the obligation -- Default of the debtor -- Effects of the obligation on third parties -- Part III Estinguishment of obligations and limitation period: Extinguishment of obligations -- Limintation period -- Part IV Joint and several debtors and creditors, conditions, earnest and forfeit money, and penalty: Joint and several debtors -- Joint and several creditors -- Conditional contracts -- Earnest money and forfeit money -- Contractual penalty -- Part V Assignment of claims, assumption of debts, transfer of contracts and joining a party to an existing contract: Assignment of claims -- Assumption of obligations -- Transfer of contracts and joining a party to an existing contract.