The index has mapping-comparator but not make-mapping-comparator.
The body text makes comparator? an exported identifier, but I see no reason why it should be exported. If you want it, import (srfi 128).
In the definition of mapping-pop, for "an arbitrary (but see below) association" read "the association with the least key". The second paragraph should read "The hashmap-pop procedure returns an arbitrary association."
In the definition of mapping-search, for "is searched" read "is searched in the order of the stored keys". Change the second paragraph to "The hashmap-search procedure searches in arbitrary order."
In the definition of mapping-find, for "arbitrarily chosen association" read "the association with the least key". Change the second paragraph to "The hashmap-find procedure searches in arbitrary order."
In the definition of mapping-keys, for "all the keys" read "all the keys in increasing order". Change the second paragraph to "The hashmap-keys procedure returns the keys in arbitrary order."
In the definition of mapping-values, for "all the values" read "all the values in increasing order of the keys". Change the second paragraph to "The hashmap-keys procedure returns the values in arbitrary order."
In the definition of mapping-entries for "The two lists" read "in increasing order of the keys. The hashmap-entries procedure returns the two lists". Drop the second paragraph.
In the definitions of mapping-map, mapping-for-each, mapping-fold: for "in arbitrary order (but see below)" read "in increasing order of the keys". Change the last paragraph to "The <whichever> procedure processes the associations in arbitrary order."
In the definition of mapping-map->list, for "for every association" read "for every association in increasing order of the keys". Change the second paragraph to "The hashmap-map->list procedure processes the associations in arbitrary order."
In the definition of mapping->alist, for "in unspecified order" read "in increasing order of the keys". Change the second paragraph to "The hashmap->alist procedure processes the associations in arbitrary order."
In the definitions of mapping/ordered and mapping-unfold/ordered, the words "if they are imported from (srfi 146)" are now superfluous. It is still an error to create a hashmap from unordered input in this function, though the error will probably not be caught.
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