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docs/lib2x-sum.md

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+# sum
+
+Use `+` to sum up all elements in a list.
+
+**Since:** 2.4
+
+## Parameters
+
+- `lt` : a list of elements that can be applied by `+`.
+
+## Examples
+
+    use <util/sum.scad>;
+
+    assert(sum([1, 2, 3, 4, 5]) == 15);
+    assert(sum([[1, 2, 3], [4, 5, 6]]) == [5, 7, 9]);