背景是说蝙蝠夜巡，存在类似一个工程的问题，如何无光时寻找猎物。

Given the questions of how to manoeuvre in the dark, what solutions might an engineer consider? The first one that might occur to him is to manufacture light, to use a lantern or a searchlight.

这里的to use a lantern or a searchlight（不像是与manufacture light并列，因为整段说的都是自己制造灯光，没有写借用别的光源）而像对manufacture light的举例补充说明做伴随/补充状语，或同位语（真题解析书上说是做manufacture light的同位语）？

但不定式做同位语主要用在特定名词后比如need to do,right to do 。不定式做方式状语主要用于as if to do sth这类结构，如：He opened his mouth as if to say something。

综上，请问to use a lantern or a searchlight是什么结构和用法？