You wrote "If the librarian's 'call for' meaning was indeed the one originally intended"
I doubt that "the librarian's 'call for' meaning was indeed the one originally intended" (not that you say it!).
Or maybe there is no difference between what you mean by "call for" and what the first quote meant by "call in". The subroutine is called / retrieved - and control is transferred to that subroutine. (I wouldn't say that when doctors are called to see a patient, for example, they are called in the librarian's meaning.)
You wrote "If the librarian's 'call for' meaning was indeed the one originally intended"
I doubt that "the librarian's 'call for' meaning was indeed the one originally intended" (not that you say it!).
Or maybe there is no difference between what you mean by "call for" and what the first quote meant by "call in". The subroutine is called / retrieved - and control is transferred to that subroutine. (I wouldn't say that when doctors are called to see a patient, for example, they are called in the librarian's meaning.)