Edit distance implementation

It is interesting that this basic question does not seem to have a ready
answer yet according to Google. (swipl +edit +distance returned 0).

A naive implementation of edit distance using iterative deepening of depth
first search runs into combinatorial blowup. The text book solution is to
provide memoization by building a table of intermediate results, basically
recursion through:
 cost(i, j) = min(cost(i-1, j)+del, cost(i, j-1)+ins, cost(i-1, j-1)+sub)

So the question comes to how best to emulate this two dimensional array in
swipl. I am thinking of using arg/3 on an arbitrarily large term. This has
to be more efficient than dynamic predicates? Any suggestion?

Thanks in advance.
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