Negative numbers Fortunately, once you can represent natural numbers, integers are quite easy to represent. The idea is quite straightforward and simply consist of representing an integer by a pair of naturals. Namely, let the integer = = (a,b) with a > 0,8 2 0. For instance, the number 20 could be represented by (20,0). An alternative representation would be (25,5). Indeed, the number 20 can be seen as 20 20-0 20 25 - 5 1 Namely, 2 = 2 - 5. The advantage arises for making the number negative. For instance, -20 = (0,20) = 0 - 20. In other words, to negate an integer you only need to swap the two naturals! Thankfully, addition is equally simple as 21+ where 21 = (a, b) and >=(c,d) is simply 21 +22=a-+c-d=a +c-b-d=a+c-(b + d) = (a + cb+d) To get a lambda expression implementing addition, it suffices to leverage the pair utilty alongside the addition over naturals (Church Numerals) to get a full fledged solution. Implement the above ideas for the following functions 1. Lambda expression for unary riegation of an integer 2. Lambda expression for successor of an integer 3. Lambda expression for predecessor of an integer 4. Lambda expression for binary addition of integers 5. Lambda expression for binary substraction of two integers 6. Lambda expression for binary multiplication of two integers Naturally, you should first follow the outline above and write the arithmetic specification of the operation before encoding it as a lambda expression