4. (a) Let {an } be a sequence. Provide a complete and accurate definition of what it means for an + co as n -+ 00. Hint : Recall from lecture how we discussed that all limits have the same 'format'. A universally quantified number, over an eristen- tially quantified number, over an implication. We spoke about what each of these 'parts' represents and corresponds to in the limit. Re- membering these and applying them to this question will help you to write down the requested definition. Alternatively, remember your infinite limit at infinity definition from A31 and adapt it to our sequence