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 }
