For example, consider the proposition “Cuius est solum eius est usque ad coelum et ad inferos” (literally: ‘for whoever owns the soil, it is theirs up to Heaven and down to Hell’). This is also known as “ad coelum.” A legal reductio ad absurdum argument against the proposition might be:
Suppose we take this proposition to a logical extreme. This would grant a land owner rights to everything in a cone from the center of the earth to an infinite distance out into space, and whatever was inside that cone, including stars and planets. It is absurd that someone who purchases land on earth should own other planets, therefore this proposition is wrong.