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Task/Set/Sidef/set-2.sidef

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+var x = Set(1, 2, 3);
+5..7 -> each { |i| x += i };
+
+var y = Set(1, 2, 4, x);
+
+say "set x is: #{x}";
+say "set y is: #{y}";
+
+[1,2,3,4,x].each { |elem|
+    say ("#{elem} is ", elem ∈ y ? '' : 'not', " in y");
+}
+
+var (w, z);
+say ("union: ", x ∪ y);
+say ("intersect: ", x ∩ y);
+say ("z = x ∖ y = ", z = (x ∖ y) );
+say ("y is ", x ⊆ y ? "" : "not ", "a subset of x");
+say ("z is ", x ⊆ z ? "" : "not ", "a subset of x");
+say ("z = (x ∪ y) ∖ (x ∩ y) = ", z = ((x ∪ y) ∖ (x ∩ y)));
+say ("w = x ^ y = ", w = (x ^ y));
+say ("w is ", w ≡ z ? "" : "not ", "equal to z");
+say ("w is ", w ≡ x ? "" : "not ", "equal to x");