Null URM Program Computes Identity Function

Theorem
The null URM program computes the identity function $I_\N: \N \to \N$, defined as:
 * $\forall n \in \N: I_\N \left({n}\right) = n$

Proof
The null URM program by definition has no instructions.

Therefore, the contents of $R_1$ remain unchanged when "running" it.