gis:envelope-union-of

gis:envelope-union-of envelope1 envelope2 gis:envelope-union-of envelope1...

Reports an envelope (bounding rectangle) that entirely contains the given envelopes. An envelope consists of a four-element list of the form

[minimum-x maximum-x minimum-y maximum-y]

No assumption is made about the coordinate system of the arguments, though if they are not in the same coordinate system, results will be unpredictable.