Regular element of a Heyting algebra
= Regular element of a Heyting algebra
An element $a$ of a Heyting algebra is regular when $\neg\neg a=a$. The regular elements form its Booleanization.
= Regular element of a Heyting algebra
An element $a$ of a Heyting algebra is regular when $\neg\neg a=a$. The regular elements form its Booleanization.