system: You are a contract-analysis assistant performing a span-extraction task. You are given an excerpt from a commercial contract and the name of a clause type to locate within it.

Return the exact text of the requested clause, copied verbatim from the excerpt — identical wording and punctuation, with no paraphrasing, summarising, explanation, or added commentary.

The excerpt is one window of a much longer contract and often will not contain the requested clause. If the requested clause does not appear in this excerpt, respond with exactly: Not found.

Output only the extracted clause text, or the exact string `Not found.` — nothing else.

user: Contract excerpt:
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actions or omissions of the SENDER, its workers, subordinates, contractors and subcontractors, except in cases of (i) gross negligence or willful misconduct by ECOPETROL, or (ii) a force majeure or unforeseen circumstances. b) The SENDER shall not be waved from its responsibility to pay the Fee agreed in this Contract, save the Service is not provided by causes exclusively attributable to ECOPETROL as indicated in numeral 11.2 b). a) ECOPETROL shall notify the SENDER within twenty four hours (24) following the moment of occurrence, making the commitment to submit all details within the following five (5) business days. 7 11.7 The fulfillment of all legal obligations corresponding to each of the Parties, among them and including, those in connection with its personnel, compliance with environmental standards, those related with the legality of intellectual property rights, tax provisions or any other similar obligation, shall be borne and will be the exclusive responsibility of the Party to whom said obligation corresponds and its failure to perform it shall only affect said Party. 11.8 The fact that any of the Parties fails to enforce to the other Party any of the stipulations hereof at any time, shall not be considered a waiver for the performance of said stipulation, unless the other Party notifies it in writing. No waiver to allege a violation of this Contract shall be considered as a waiver to allege any other violation. 11.9 The Parties state to be aware of the public order and security conditions of the areas in which the purpose of the Contract shall be developed, and each Party assumes its own and exclusive responsibility for the risks derived from such conditions, and therefore, shall not take any claim or action against the other Party due to any damage or injuries suffered by said Party on its property, personnel, its agents, contractors or subcontractors (including its employees or subordinates) resulting from public order or security conditions. 11.10 Each Party shall be exclusively responsible for any damage caused to third parties as a result of its proved and exclusive fault. In particular, each Party shall be responsible for all loss or damage to the property of third parties or injury, illness or death of all third parties as a result of its acts or omission or those from its personnel. CLAUSE TWELFTH PENAL PECUNIARY CLAUSE 12.1 In case of failing to fulfill the obligations of the SENDER as a result of any actions or illegal omissions or deviations from the Contract, the SENDER agrees to pay ECOPETROL as a penalty, an amount equivalent to ten percent (10%) of the final value of the Contract. 12.2 Said sum shall be charged to the amount of damage suffered by ECOPETROL, and its value may be taken directly from the balance in favor of the SENDER if there is any, or else from the Bond. If this is not possible, the penal pecuniary clause shall be collected by means of execution for which the Contract shall be a writ of execution. 12.3 The application of the penal pecuniary clause does not include the indemnification for any damages borne by the SENDER if the amounts of these are higher, under the criteria of ECOPETROL, to the amount of the penal pecuniary clause agreed hereof, nor it releases the SENDER from its payment obligation of the totality of the value of the Contract pursuant to the conditions agreed. b) ECOPETROL shall carry out all reasonable procedures as required to resume as soon as possible the performance of the obligations of the Contract. Likewise, it shall make efforts to minimize or mitigate any delay or additional costs that may be generated. 8 CLAUSE THIRTEENTH SUSPENSION DUE TO NON-PERFORMANCE OF THE SENDER 13.1 ECOPETROL shall be entitled to suspend the Service in case of any events that may represent a serious default on any of the obligations of the SENDER. For this purpose, a communication from ECOPETROL addressed to the SENDER shall be sufficient, notifying the serious default. ECOPETROL may, based on the seriousness and the effects of the default, grant the SENDER a reasonable term to fix the default (the "Grace Period"), which under no circumstance may be granted if the default is due to the non-payment of the Fee in the terms set out in the Contract hereof. If, upon expiration of the Grace Period the SENDER has not resolved the default, ECOPETROL may suspend the Service and the SENDER shall not be entitled to any indemnification under no circumstance. The reestablishment
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Extract the exact clause related to "Anti-Assignment" from the excerpt above.