不ふ変へん性せいふへんせいMeanings1nouninvariancemathematicsTechnical term used in mathematics and related fields to describe a property that remains unchanged under transformations.この方ほう程てい式しきの不ふ変へん性せいを証しょう明めいする必ひつ要ようがある。We need to prove the invariance of this equation.