Definition:Complement


 * Complementary angles: two angles whose measures add up to the measure of a right angle.


 * Complement of Relation: for a relation $$\mathcal{R}$$, its complement is all those pairs which are not in $$\mathcal{R}$$.


 * Set Complement or Relative Complement: two related concepts: all the elements of a set which are not in a given subset.


 * Logical Complement: In logic and boolean algebra, the negation of a statement or boolean function.


 * Complement of Graph: a graph with the same vertex set but whose edge set is all those edges not in that graph.