User blog comment:GamesFan2000/There aren't enough particles in the universe to solve a four-entry array/@comment-30754445-20181129104403/@comment-30754445-20181129235903

Yeah, sorry. I mis-copied what you wrote.

But you shouldn't have gotten {4,4,{4,4,4→4→4},2} either.

The only point in the calculation where {4,4,X,2} (for some large X) appears, is in the expansion of {4,3,1,3}:

{4,3,1,3} = {4,4,{4,2,1,3},2} = {4,4, {4,4,4,2}, 2}, with {4,4,4,2} being much much larger than {4,4,4→4→4}.

And the only point where {4,4,4→4→4} appears comes a bit later, after we've completed the initial expansion all the way to an innermost {4,4,4}. Now we need to start evaluating the actual numbers, where the innermost portion of the array is:

{...{4, {4,4, {4,4, {4,4,4}}}, 1,2}...}

So the beginning of our evaluation would look like this:

{...{4, {4,4, {4,4, {4,4,4}}}, 1,2}...} =

{...{4, {4,4, {4,4, 4→4→4}}, 1,2}...} =

{...{4, {4,4, 4→4→(4→4→4)}, 1,2}...} =

{...{4, 4→4→(4→4→(4→4→4)), 1, 2}...}

With the last expression being somewhat similar to the one you've written. But note that this array is of the form {4,X,1,2} rather than {4,4,X,2}.