Wiktionary
maplet
Etymology 1 n. (context computing mathematics English) An applet written in the computer algebra system (w Maple (software) Maple). Etymology 2
n. (context mathematics English) A pair which is a member of a mapping.
Wikipedia
Maplet
A maplet or maplet arrow (symbol: ↦, commonly pronounced "maps to") is a symbol consisting of a vertical line with a rightward-facing arrow. It is used in mathematics and in computer science to denote functions (the expression x ↦ y is also called a maplet). One example of use of the maplet is in Z notation, a formal specification language used in software development.
In the Unicode character set, the maplet is at the point U+21A6.