It is as if you looked up, say, infer/imply in a usage manual and the author's treatment, in place of an explanation and sound advice, were an unpleasant diatribe against anyone so dense and rude as to have had to look up the entry to begin with.
( It ( ( is ( as ( ( if ( you ( ( looked ( ( ( ( up , ) say ) , ) infer/imply ) ) ( in ( ( ( a ( usage manual ) ) and ) ( ( the ( author 's ) ) treatment ) ) ) ) ) ) ( , ( ( in ( place ( of ( an ( explanation ( and ( sound advice ) ) ) ) ) ) ) ( , ( were ( ( an ( unpleasant diatribe ) ) ( against ( anyone ( ( ( so dense ) and ) ( ( rude as ) ( to ( have ( had ( to ( ( look up ) ( the ( entry ( to ( begin with ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (SBAR (IN as) (S (SBAR (IN if) (S (NP (PRP you)) (VP (VBD looked) (PP (IN up) (, ,) (INTJ (VB say)) (, ,) (ADVP (RB infer/imply))) (PP (IN in) (NP (NP (DT a) (NN usage) (NN manual)) (CC and) (NP (NP (DT the) (NN author) (POS 's)) (NN treatment))))))) (, ,) (PP (IN in) (NP (NP (NN place)) (PP (IN of) (NP (DT an) (NN explanation) (CC and) (NN sound) (NN advice))))) (, ,) (VP (VBD were) (NP (NP (DT an) (JJ unpleasant) (NN diatribe)) (PP (IN against) (NP (NP (NN anyone)) (ADJP (ADJP (RB so) (JJ dense)) (CC and) (ADJP (JJ rude) (RB as) (S (VP (TO to) (VP (VB have) (VP (VBN had) (S (VP (TO to) (VP (VB look) (PRT (RP up)) (NP (DT the) (NN entry) (S (VP (TO to) (VP (VB begin) (PP (IN with)))))))))))))))))))))) (. .)))
Replacing the explanation with the author's diatribe would only work in textbooks written by famous professors.
( ( ( Replacing ( the explanation ) ) ( with ( ( the ( author 's ) ) diatribe ) ) ) ( ( ( would only ) ( work ( in ( textbooks ( written ( by ( famous professors ) ) ) ) ) ) ) . ) )
(ROOT (S (S (VP (VBG Replacing) (NP (DT the) (NN explanation)) (PP (IN with) (NP (NP (DT the) (NN author) (POS 's)) (NN diatribe))))) (VP (MD would) (ADVP (RB only)) (VP (VB work) (PP (IN in) (NP (NP (NNS textbooks)) (VP (VBN written) (PP (IN by) (NP (JJ famous) (NNS professors)))))))) (. .)))