“so agree/request/declare/其他动词”结构中的so是为了避免重复文中提到的内容，相当于动词+the same结构。

翻译时，最简单的译法是“所+动词”“这些/这样+动词”，也可以根据具体场景作具体翻译。

如

Unless the buyer has received notice from the seller that he will not perform within the period so fixed, the buyer may not, during that period, resort to any remedy for breach of contract. However, the buyer is not deprived thereby of any right he may have to claim damages for delay in performance.

除非买方收到卖方的通知,声称他在所规定的时间内将不会履行义务，买方在这段时间内不得对违反合同采取任何补救措施。但是，买方并不因此丧失他对迟延履行义务可能享有的要求损害赔偿的任何权利。

BUYER reserves the right at any time to make changes in the PURCHASE ORDER, If such changes cause an increase or decrease in SELLER's costs or alteration in the date of delivery, SELLER shall so advise BUYER

买方有权任何时候对采购订单作出变更。如果这种变更致使卖方费用增加或减少或交货日期变化,卖方应将这些情况通知买方。

The SELLER shall provide written evidence of compliance with all permits, laws and regulations within 7 days of being so requested by the BUYER.

如果买方这样要求,卖方应在7日内提供书面证据表明其遵守所有的许可、法律法规。

例句来源《英文合同阅读与分析技巧》