[Oops.] Grammar mistake: "an" instead of "a"

[tbell5]

Please verify that the error is present in the most recent revision before reporting.

Chapter number or note title: [title] 1

Page number: [page] 26

Error description: [error] In footnote 5 it says, "described an non-recursive variant", but it should be "described a non-recursive variant".

Suggested fix (if any): [fix] "an" --> "a"

[tbell5]

Nevermind, this issue was already raised in #176