Purpose
Fetch the parent of a parse tree node if one exists. Only the leftmost parse tree node in a list has a parent.
Syntax
returnedPnode = pnup(aPnode)
returnedPnode - type: pnode
aPnode - type: pnode
Returns
Remarks
Pnup is a primitive that does not fetch the parent. (An NLP++ pnparent function is called for or can be written by the user.)