pro-numeral: the most-recently mentioned full/complete numerical or mathematical string/expression.

For clarity, whole strings are taken; therefore, in "pare", the string which would be referenced by this word is all of "pare" (and not just "re"). Back-counting rules the same as or analogous to those for "ri". This word functions essentially as "ri" does, but for numbers (PA*) and mekso (including VUhU) - and, in particular, ignores other sumti, unless marked with "li" (in which case, "li" is included in the reference – which may require various adjustments if this word is used in in contexts which disallow the introduction of another/new sumti or which would take on an undesirable semantic or syntactic interpretation if another sumti were introduced where this word is used). Letteral strings which act as numerical/mathematical variables are within the scope of potential reference, but not those which do not (unless they are somehow used in a mathematical expression which is being referenced as a whole); quotations and abstractions behave as the latter case for letteral strings wrt this word. Within a mekso expression, "du" and other predicates are taken as terminating a numerical expression; this word (unless subscripted; see infra) references completed numerical/mathematical expressions, and thus will not refer to the one in which it itself appears, which should help to avoid self-reference, predication issues, non-terminating loops, nondefinition issues, etc. Thus, it might be useful for recursive definitions. Subscript this word with an integer n in order to refer count n potential referents back (positive n is back-counting, n = 0 refers to the current numerical/mathematical expression in which this subscripted word is embedded (once completed and fully evaluated, if such terminates), and negative n is forward-counting). Can be used for quantifying sumti; "one hundred men and horses" probably means "one hundred men and one hundred horses", and the latter "one hundred" can be replaced by this word, because numerical/mathematical expressions which function as quantifiers are nonetheless numerical/mathematical expressions (and tend to be completed). Even in a recursive or self-referential context, once the referenced/pointed-to expression is evaluated, the value which it takes in its most-recent usage is the one which should be substituted in place of this word; use "ra'o" in order to update it if such is desired (and the value depends to some extent on the new context or other developments).