Your first example, the single-assignment-form, is unreadable because the chosen names are utterly meaningless and you have extremely low information-density. That might be an artifact of trying not to disclose internal information on your part, the true code might be fine in that respect, we cannot say. Anyway, it's long-winded, which does not generally lend itself to easy understanding.

Your second example is condensed to an absurd degree. If the functions had useful names, that might be fine and well readable because there isn't too much of it, but as-is it's confusing in the other direction.

After introducing meaningful names, you might look whether one of the forms seems natural, or if there's a golden middle to shoot for.

Now that you have readable code, most bugs will be obvious, and the others at least have a harder time hiding from you.

Your first example, the single-assignment-form, is unreadable because the chosen names are utterly meaningless. That might be an artifact of trying not to disclose internal information on your part, the true code might be fine in that respect, we cannot say. Anyway, it's long-winded due to extremely low information-density, which does not generally lend itself to easy understanding.

Your second example is condensed to an absurd degree. If the functions had useful names, that might be fine and well readable because there isn't too much of it, but as-is it's confusing in the other direction.

After introducing meaningful names, you might look whether one of the forms seems natural, or if there's a golden middle to shoot for.

Now that you have readable code, most bugs will be obvious, and the others at least have a harder time hiding from you.