可逆 かぎゃく変化 へんかではありませんでした
hikagyakuhenkadewārimasendeshita

Noun
Desu Copula

The polite, past negative form of 非可逆変化

1. Was not an irreversible change.; Was not a non-reversible change.

Past/Perfective
Negative
Polite
Formal Register