cond %{SEND_RESPONSE_HDR_HOOK} [AND]
cond %{CLIENT-URL:PATH} /\/alpha\//
    if
        cond %{CLIENT-HEADER:X-Branch} ="alpha" [AND]
        cond %{GROUP}
            cond %{CLIENT-HEADER:X-Sub-A} ="" [OR,NOT]
            cond %{CLIENT-HEADER:X-Sub-B} ="" [NOT]
        cond %{GROUP:END}
            set-header X-Result "alpha"
        elif
            cond %{CLIENT-HEADER:X-Branch} ="beta"
                set-header X-Result "beta"
        else
            set-header X-Result "other"
    endif
