SymMAP.NET
SymMAP.NET is an open source project attempting to support symbol lang
...For now, only the following symbol operation are supported:
p(lat,lon) : define a point with lat and lon. The point name can be any name, preferrably lower case for the first letter.
A[p1, p2, ..., pn] : A represents one set of points, while p* (or any name, preferrably lower case for the first letter) represents n points. Define a set A with n points.
A+B: A represents one set of points, while B represents another set. Applying '+' symbol will aggregate A and B and assign the results to A.
A-B: Similarly, Applying '-' symbol will remove the common subset of A and B from A, then assign the results to A.
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