Smith's rule as a word RAM program in IMP+: it reads the standard word into memory, copies the processing times and weights into two arrays, sorts the jobs by bottom-up merge sort with the comparison $p_i w_j ≤ p_j w_i$ (jobs of weight $0$ last) in $⌈log₂ n⌉$ passes of linear cost, adds up the weighted completion times of the sorted order and compares with the threshold. Run in this order without idle time, the jobs pay $Σ w_j p_j$ plus, for every pair, the smaller of $p_i w_j$ and $p_j w_i$, and every schedule on one machine pays at least that (the jobs before each job in the order of completion fill the machine up to its completion).