+[ t ] [ 4 { 2 4 5 } in? ] unit-test
+[ f ] [ 1 { 2 4 5 } in? ] unit-test
+
+[ V{ 1 2 3 } ] [ 3 V{ 1 2 } clone [ adjoin ] keep ] unit-test
+[ V{ 1 2 } ] [ 2 V{ 1 2 } clone [ adjoin ] keep ] unit-test
+[ V{ 1 2 } ] [ 3 V{ 1 2 } clone [ delete ] keep ] unit-test
+[ V{ 2 } ] [ 1 V{ 1 2 } clone [ delete ] keep ] unit-test
+
+[ t ] [ { 1 2 3 } { 2 1 3 } set= ] unit-test
+[ f ] [ { 2 3 } { 1 2 3 } set= ] unit-test
+[ f ] [ { 1 2 3 } { 2 3 } set= ] unit-test
+
+[ { 1 } ] [ { 1 } members ] unit-test
+
+[ { 1 2 3 } ] [ { 1 1 1 2 2 3 3 3 3 3 } dup set-like natural-sort ] unit-test
+[ { 1 2 3 } ] [ HS{ 1 2 3 } { } set-like natural-sort ] unit-test
+
+[ HS{ 1 2 3 } ] [ { 1 2 3 } fast-set ] unit-test
+
+[ { 1 2 3 } ] [ { { 1 } { 2 } { 1 3 } } combine ] unit-test
+
+[ f ] [ { 0 1 1 2 3 5 } all-unique? ] unit-test
+[ t ] [ { 0 1 2 3 4 5 } all-unique? ] unit-test
+
+[ { 1 2 3 } ] [ { 1 2 2 3 3 } { } set-like ] unit-test
+[ { 3 2 1 } ] [ { 3 3 2 2 1 } { } set-like ] unit-test
+
+[ { 2 1 2 1 } ] [ { 1 2 3 2 1 2 1 } duplicates ] unit-test
+[ f ] [ HS{ 1 2 3 1 2 1 } duplicates ] unit-test
+
+[ H{ { 3 HS{ 1 2 } } } ] [ H{ } clone 1 3 pick adjoin-at 2 3 pick adjoin-at ] unit-test