olemus
printsiip: eituse eitus on jaatus
=
the principle that a statement is equivalent to the denial of its negation

näide
Boole'i algebras: samasus ¬¬ a= a

ülevaateid
https://en.wikipedia.org/wiki/Double_negation

https://www.encyclopediaofmath.org/index.php/Double_negation,_law_of

https://proofwiki.org/wiki/Double_Negation

vt ka
https://en.wikipedia.org/wiki/Double_negative