You cannot compute DMOD 12(0) directly—it is not a number. Naive finite differencing produces nonsense (infinite or NaN values). For example, the central difference formula for the 12th derivative diverges as step size → 0 unless the function is 12x differentiable, which |x| is not.

**If your request

Numbers coprime with 12 (have multiplicative inverses modulo 12): 1, 5, 7, 11