information:filtering, quality:corruption
Notation

Various notations are used in the literature to denote that two elements a {\displaystyle a} and b {\displaystyle b} of a set are equivalent with respect to an equivalence relation R; {\displaystyle R;} the most common are " a ∼ b {\displaystyle a\sim b} " and " a ≡ b ", which are used when R {\displaystyle R} is implicit, and variations of " a ∼ R b {\displaystyle a\sim _{R}b} ", " a ≡ b ", or " a R b {\displaystyle {a\mathop {R} b}} " to specify R {\displaystyle R} explicitly. Non-equivalence may be written " a ≁ b " or " a ≢ b {\displaystyle a\not \equiv b} ".