a>  b { color: red }
a>  b { color: red }
a >  b { color: red }
a+  b { color: red }
a+  b { color: red }
a +  b { color: red }
a~  b { color: red }
a~  b { color: red }
a ~  b { color: red }
a ~  b+  c>  d { color: red }
