// equality and inequality of sets
if {} == {} then println "{}=={}"; fi;
if {} != {} then println "{}!={}"; fi;
if {} == {1} then println "{}=={1}"; fi;
if {1} != {} then println "{1}!={}"; fi;
if {1} == {1} then println "{1}=={1}"; fi;
if {1} != {1} then println "{1}!={1}"; fi;
if {1,2,3,4} == {1,2,3,4} then println "{1,2,3,4}=={1,2,3,4}"; fi;
if {1,2,3,4} != {1,2,3,4} then println "{1,2,3,4}!={1,2,3,4}"; fi;
if {1,2} == {1,2,3,4} then println "{1,2}=={1,2,3,4}"; fi;
if {1,2} != {1,2,3,4} then println "{1,2}!={1,2,3,4}"; fi;
if {1,2,2,4} == {1,2,3,4} then println "{1,2,2,4}=={1,2,3,4}"; fi;
if {1,2,2,4} != {1,2,3,4} then println "{1,2,2,4}!={1,2,3,4}"; fi;
if [1,4] == [2,5] then println "[1,4]==[2,5]"; fi;
if [1,4] != [2,5] then println "[1,4]!=[2,5]"; fi;


// Order (subset) comparisons
if {} <= {} then println "{}<={}"; fi;
if {} < {} then println "{}<{}"; fi;
if {} >= {} then println "{}>={}"; fi;
if {} > {} then println "{}>{}"; fi;
if {1,2,3} <= {1,2,3} then println "{1,2,3}<={1,2,3}"; fi;
if {1,2,3} < {1,2,3} then println "{1,2,3}<{1,2,3}"; fi;
if {1,2,3} >= {1,2,3} then println "{1,2,3}>={1,2,3}"; fi;
if {1,2,3} > {1,2,3} then println "{1,2,3}>{1,2,3}"; fi;
if {1,2,3} <= {0,1,2,3,10} then println "{1,2,3}<={0,1,2,3,10}"; fi;
if {1,2,3} < {0,1,2,3,10} then println "{1,2,3}<{0,1,2,3,10}"; fi;
if {1,2,3} >= {0,1,2,3,10} then println "{1,2,3}>={0,1,2,3,10}"; fi;
if {1,2,3} > {0,1,2,3,10} then println "{1,2,3}>{0,1,2,3,10}"; fi;
if {0,1,2,3,10} <= {1,3} then println "{0,1,2,3,10}<={1,3}"; fi;
if {0,1,2,3,10} < {1,3} then println "{0,1,2,3,10}<{1,3}"; fi;
if {0,1,2,3,10} >= {1,3} then println "{0,1,2,3,10}>={1,3}"; fi;
if {0,1,2,3,10} > {1,3} then println "{0,1,2,3,10}>{1,3}"; fi;
if {0,1,2,3,10} <= [2,5] then println "{0,1,2,3,10}<=[2,5]"; fi;
if {0,1,2,3,10} < [2,5] then println "{0,1,2,3,10}<[2,5]"; fi;
if {0,1,2,3,10} >= [2,5] then println "{0,1,2,3,10}>=[2,5]"; fi;
if {0,1,2,3,10} > [2,5] then println "{0,1,2,3,10}>[2,5]"; fi;


// Element operators
if 1 =in {} then println "1 =in {}"; fi;
if 1 !in {} then println "1 !in {}"; fi;
if 3 =in {1,2,3} then println "3 =in {1,2,3}"; fi;
if 2 !in {1,2,3} then println "2 !in {1,2,3}"; fi;
if 3 =in {1,2,5} then println "3 =in {1,2,5}"; fi;
if 2 !in {1,20,3} then println "2 !in {1,20,3}"; fi;