Grammar, Punctuation and Capitalization - Handbook for Technical ...

Chapter 3. Punctuation Page 50ClauseParticipal phraseGerund phraseInfinitive phraseAlthough some mathematicians are not comfortable withthis intuitive definition, it is widely used.Called mean square calculus, this theory is based on theconcept of mean square convergence.In analyzing the experiment, we try to statistically describethe whole random process.To understand this concept, note that periodic functionsmay be expanded in Fourier series.• The comma is optional after a short introductory adverbial phrase unless the comma is required for clarity:EitherOrWrongBetterIn recent years, the delta function has been rigorouslydefined.In recent years the delta function has been rigorouslydefined.Soon after the photon density becomes steady as gains andlosses balance each other.Soon after, the photon density becomes steady as gains andlosses balance each other.• Do not place a comma after an introductory phrase that immediately precedes the verb it modifies:WrongCorrectOnly in recent years, has the delta function been rigorouslydefined.Only in recent years has the delta function been rigorouslydefined.Remember that after introductory clauses and phrases the comma is separating, not enclosing. A comma isappropriate after an internal phrase or clause, but it is not appropriate before unless the phrase or clause isnonrestrictive (see section commasenclose).• A comma follows, but does not precede, restrictive introductory elements:WrongRecombination rate is larger than quenching rate, and, afterlasing is achieved, both are smaller than photo-breakdissociation rate.CorrectRecombination rate is larger than quenching rate, and afterlasing is achieved, both are smaller than photo-breakdissociation rate.Wrong The laser pulse was reasonably stationary, although, at 1.6msec, motion of the arc is evident.Correct The laser pulse was reasonably stationary, although at 1.6msec,motion of the arc is evident.• A comma both precedes and follows nonrestrictive introductory elements: