connective N1 rare writtenliterary
〜であろうと〜であろうと — whether ~ or ~
〜であろうと〜であろうと
Builds on 〜であれ〜であれ
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See 〜であろうと〜であろうと in real sentences
Jengo shows 〜であろうと〜であろうと the way you actually meet it: inside real Japanese sentences, so it sticks instead of staying an abstract rule.
Study it in JengoSources Compiled with reference to A Dictionary of Advanced Japanese Grammar. Editorial confidence: medium.