The following axis contains all nodes in the same document as the context node that are after the context node in document order, excluding any descendants and excluding attribute nodes and namespace nodes.
/AAA/XXX/following::*
//ZZZ/following::*
The preceding axis contains all nodes in the same document as the context node that are before the context node in document order, excluding any ancestors and excluding attribute nodes and namespace nodes
/AAA/XXX/preceding::*
//GGG/preceding::*
The descendant-or-self axis contains the context node and the descendants of the context node
/AAA/XXX/descendant-or-self::*
//CCC/descendant-or-self::*
The ancestor-or-self axis contains the context node and the ancestors of the context node; thus, the ancestor-or-self axis will always include the root node.
/AAA/XXX/DDD/EEE/ancestor-or-self::*
//GGG/ancestor-or-self::*
The ancestor, descendant, following, preceding and self axes partition a document (ignoring attribute and namespace nodes): they do not overlap and together they contain all the nodes in the document.
//GGG/ancestor::*
//GGG/descendant::*
//GGG/following::*
//GGG/preceding::*
//GGG/self::*
//GGG/ancestor::* | //GGG/descendant::* | //GGG/following::* | //GGG/preceding::* | //GGG/self::*
The div operator performs floating-point division, the mod operator returns the remainder from a truncating division. The floor function returns the largest (closest to positive infinity) number that is not greater than the argument and that is an integer.The ceiling function returns the smallest (closest to negative infinity) number that is not less than the argument and that is an integer.
//BBB[position() mod 2 = 0 ]
//BBB[ position() = floor(last() div 2 + 0.5) or position() = ceiling(last() div 2 + 0.5) ]
//CCC[ position() = floor(last() div 2 + 0.5) or position() = ceiling(last() div 2 + 0.5) ]
