Let a patch be given by the map 
, where 
is an open subset of 
, or more generally by 
, where 
is any subset of 
. Then 
(or more generally, 
) is called the trace of 
.
Map Trace
See also
PatchExplore with Wolfram|Alpha
References
Gray, A. Modern Differential Geometry of Curves and Surfaces with Mathematica, 2nd ed. Boca Raton, FL: CRC Press, pp. 269-270, 1997.Referenced on Wolfram|Alpha
Map TraceCite this as:
Weisstein, Eric W. "Map Trace." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/MapTrace.html