Creates and returns a Term that represents a selector of a term in a
triple :
First = "\x1.x1\x2x3x4.x2"
Second = "\x1.x1\x2x3x4.x3"
Last = "\x1.x1\x2x3x4.x4"
size() -
Method in class org.xmloperator.lambda2.net.impl.StackImpl
size() -
Method in interface org.xmloperator.lambda2.net.model.Stack