(10 pts) Let P(x) be a computable predicate. Show that the function f defined by: f(x1,x2)={x1+x2ifP(x1+x2) otherwise } is partially computable. (10) Let be a computable permutation (i.e. one-one onto function) of N and let 1 be the inverse of , i.e., 1(y)=x if and only if (x)=y. Show that 1 is computable