\version "2.3.4"

\header {
texidoc ="Hairpin crescendi may be dashed. "

}

\score {
     \relative c' {
	\override Hairpin  #'dash-fraction = #0.4
	\override Hairpin  #'dash-period = #1
	f2\< g c1 d4\> b a gis\! }     
    }
