Old notations in an article

Question

I am reading an old article on group theory. During the proof of one of the theorem there is a statement as follows: "there is an isomorphism of $U$ onto $V$ which maps $G$ qua subgroup of $U$ identically onto $G$ qua sub group of $V$", I do not understand what they mean by "qua"

Answer 1

Qua : in the capacity or character of.

It's a conjunction. A re-writing of the sentence could be:

There is an isomorphism of $U$ onto $V$ which maps $G$, acting as a subgroup of $U$, identically onto $G$, acting as a subgroup of $V$.