Re: Predicate for true lists

[Paul Eggert]

Drew Adams wrote:
> They both are rare, and there doesn't seem to be much
> difference in their frequencies

Just looking at n-grams is not sufficient. You need to look how the terms are 
actually used.

I just now checked Google Books for books published in the 21st century. 
Searching for "proper list" (with the quotes in the search) got a significant 
number of relevant hits from Lispish books, with a smattering of Prolog. There 
were also quite a few irrelevant hits.

Searching for "true list" (again, quoted) got zero relevant hits. The "true 
list" hits from programming books were like this one, from page 94 of "Practical 
OCaml":

  # List.mem 50 example_list;;
  - : bool = true
  # List.mem 100 example_list;;
  - : bool = false

That is, these hits did not represent usage "true list" to mean a 
null-terminated list.

From this survey, it appears that the unanimous preference in recent published 
books is for "proper list" over "true list".