crescendi/decrescendi on one note in Lilypond? and how does a pianist do this?

[Kenneth Wolcott]

Hello;

  I have another simple engraving question.

  I frequently see a crescendo or decrescendo on a single note
(usually a whole note).

  How does a pianist do this? I can see a wind instrument or even a
string instrument doing this.

  And, even more importantly, how to engrave this?

  Two measure screenshot provided: first measure I understand; the
second measure I don't.

Thanks,
Ken

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