to the extent单独使用时，表示“达到...的程度/范围”，如

The Contractor shall design (to the extent specified in the Con-tract),execute and complete the Works in accordance with the Contract and with the Engineer's instructions, and shall remedy any defects in the Works.

承包商应按照合同的规定以及工程师的指示(在合同规定的范围内)对工程进行设计、施工和竣工,并修补其任何缺陷。

If the Contractor fails to comply with the instruction, the Employer shall be entitled to employ and pay other persons to carry out the work. Except to the extent that the Contractor would have been entitled to payment for the work, the Contractor shall subject to Sub-Clause 2..5 [ Employer's Claims] pay to the Employer all costs arising from this failure.

如果承包商未能遵守该指示,则雇主有权雇用并付款要求其他人来实施工作。除非承包商有权获得该工作的付款,否则他应按照第2.5款【雇主的索赔】的规定,向雇主支付因其未完成工作而产生的费用。

If and to the extent，这一短语在合同中通常用来限定某项条款的适用性。它表明合同的某个部分仅在特定条件满足时才适用，并且该适用性的程度取决于这些条件的实现程度。这种表达方式用来提供灵活性，使合同能够适应不同情况的发生。常译为“如果且仅限于”，如

Any such instruction shall constitute a Variation if and to the extent that it causes the Contractor to incur Unforeseeable Cost. Services for these personnel and other contractors may include the use of Contractor's Equipment, Temporary Works or access arrangements which are the responsibility of the Contractor.

如果且仅限于此类指示使承包商产生了不可预见的费用,则该指示构成了变更。为这些人员和其他承包商提供的服务包括使用承包商的设备，承包商负责的临时工程或道路通行安排。

If and to the extent that the Contractor encounters physical conditions which are unforeseeable,gives such a notice, and suffers delay and/or incurs Cost due to these conditions, the Contractor shall be entitled subject to Sub-Clause 20.1 [Contractor's Claims] to claims.

如果且仅限于承包商遇到了不可预见的外界条件,发出了通知，且因此遭致延误和/或产生了费用,承包商应有权依据第20.1款【承包商的索赔】要求索赔。

where and to the extent，也是一种表达条件和限定的短语，用于指明某条款仅在特定场合或条件下，并在这些条件的具体范围内适用，常译为“如果且仅当”，如

Where and to the extent that both the carrier and the actual carrier are liable , their liability is joint and several.

如果且仅当承运人和实际承运人均须负责时,他们负有连带责任。

参考《英文合同阅读与分析技巧》