Thanks- I assumed 13 was the clue number not part of the clue. It's always confusing when clues are not written correctly on here.
My online dictionary says "Notes: forego means to go before or precede (as in fore) and to do without is to forgo ", which is how I was always taught to spell them (and when I used to rely on Fowler), but I see that both spellings are now used in some dictionaries.