Statement (i) implies (ii) directly from the definition: if $A$ is <computably enumerable set>[computably enumerable], its semidecision program computes a <partial computable function> whose domain is exactly $A$; for example, return the empty word whenever the program halts.

Solution

Past exam of the mathematics course of the University of Cambridge / 2023 / ii / Paper 2 / 4I / b / i / Solution

 Solution (source code)