While I applaud the stated (and admirably well-
Cognomen, in fn. †, defines an “increment function” (add “I” to the end of the previous Roman number) and three sets of rewrite rules:
These rules will get you up to the “maximum” standard Roman numeral, MMMCMXCIX (3,999), but once you introduce the apostrophus (ↁ) or vinculum (V̅) to go beyond 4,000, the need for additional specific rules rears its ugly head.
Of course, there is an obvious abstract generalization to the rules to be made, after we introduce just a little bit of handy notation to represent abstract collections of 1-based units and 5-based hands:
U = “unit” or 1× symbol (I, X, C, M, X̅/ↂ, C̅/ↈ)
Ui = 1×10i
U0 = I;
U1 = X;
U2 = C;
U3 = M;
U4 = X̅ or ↂ;
etc.
H = “hand” or 5× symbol (V, L, D, V̅/ↁ, L̅/ↇ, D̅)
Hi = 5×10i
H0 = V;
H1 = L;
H2 = D;
H3 = V̅ or ↁ;
etc.
The Cyclic Generalized Roman Numeral Rewrite Rules follow immediately:
If we introduce one more abstract symbol for 2-based duals...
Ꙫ = “dual” or 2× symbol (J, Y, G, N, Y̅, G̅)
Ꙫi = 2×10i
Ꙫ0 = J;
Ꙫ1 = Y;
Ꙫ2 = G;
Ꙫ3 = N;
etc.
...then Cognomen’s (unstated!) Numeri++ Rewrite Rules can be Generalized thusly:
Cognomen’s own comment on his original Roman Numeral Rewrite Rules still ring true:
Honestly, it seems pretty straightforward when you look at it like this... This also goes to show that most subjects are amenable to linguisticky interpretation if you look hard enough. Ah, Linguistics! Is there anything it can’t do!?
Id est factum, Iōannēs!