A multivalued function (multifunction) is a relation like a function. A multifunction associates each input with at least one output. A strict function associates each input with exactly one output. An example of a multivalued function is the square root. Every complex number (except for 0), has two square roots. Example: could be 2 or -2 because and .
- "multi-valued function in nLab". Ncatlab.org. 2010-09-15. http://ncatlab.org/nlab/show/multi-valued+function. Retrieved 2011-11-11.