surjections
/sərˈdʒɛkʃənz/
noun
- In mathematics, a function that maps every element of the output set to at least one element of the input set; also called an onto function.
- In algebra class, we learned that surjections are functions where every value in the second set is used at least once.
- To prove a function is a surjection, you must show that every possible output has a matching input.
- The teacher drew a diagram showing surjections as arrows that cover all the points in the target set.