Returns a sorter-predicate that returns true if it follows the KEYS-AND-PREDICATES specification. KEYS-AND-PREDICATES is a list of key-predicate pairs: (<key> <predicate>), where precidence of key-predicate pair is based on order in KEYS-AND-PREDICATES list. E.g., if ((first <) (second <) (third <)), then the sorter-predicate will first check wether the first item of one list is < the first item of another, then the second, etc. The sorter-predicate is used for performing a multi-sort using a sorting function that uses a predicate (such as SORT). In COLAB, this is used by SORT-SPACE.