Maps to
mathematical symbol to denote a function

The maps to symbol, ↦, is a rightward arrow protruding from a vertical bar. It is used in mathematics and in computer science to denote functions.
In Z notation, a specification language used in software development, this symbol is called the maplet arrow and the expression x ↦ y is called a maplet.
In separation logic it denotes the contents of a specific cell of memory.
In the Unicode character set, the symbol is code point U+21A6.
Other uses
The "Maps to" operator is useful when it is desirable to avoid assigning names to functions.
This can avoid possible misinterpretations due to poor naming conventions, such as avoiding the following name conflict from these two functions existing in the same file or in the same mathematical proof:
func sqr:
x
↦
x
∗
x
{\displaystyle x\mapsto x*x}
Squares the input value
func sqr:
x
↦
(
2
∗
x
)
+
(
2
∗
x
)
{\displaystyle x\mapsto (2*x)+(2*x)}
.
Calculates the perimeter of a square when given an input side length.
This brief starts where responsible research should: with the source description of “Maps to” as mathematical symbol to denote a function. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the general reference register because the source frames it as mathematical symbol to denote a function. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Jul 10, 2026. The linked authority identifier is Q6754055. None of the 0 selected statements returned an explicit reference.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Maps to”, its source revision and the description used here.
- Expand the search: follow Maps to primary sources, Maps to archive and Maps research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Maps to”?
- Which cited source is closest to the event, object or claim?
- What terminology or title could unlock a more precise catalogue search?
Search terms from this dossier
This entry incorporates text from “Maps to” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.