Final answer:
The definitions are for functions that add elements to the beginning or end of a list in programming.
Step-by-step explanation:
Explanation of Code Definition The provided code snippets are definitions for two functions that manipulate lists in a computer programming context. The function cons is defined to add an element x at the beginning of a list xr, while the function snoc adds an element x at the end of the list xr. Considering the provided options and understanding the definitions, it is clear that they define functions for adding elements at either the beginning or the end of a list. Therefore, this is related to list manipulation operations commonly found in functional programming languages.
The given definitions are defining functions for adding elements at the beginning and end of a list. The first definition, fun {cons x xr} x|xr end, adds an element x at the beginning of the list xr. The second definition, fun {snoc xr x} x|xr end, adds an element x at the end of the list xr.These definitions are commonly used in computer programming to manipulate lists. By using these functions, it becomes easier to modify lists by adding elements either at the beginning or at the end.Write the final answer in 20 words: a) Functions for adding elements at the beginning and end of a list.