Problem with tempo marking and processing

[Francesco Spiga]

Hi.
I'm trying to insert movement titles in the beginning of measure.
For example, I have the following file called "example.ly":

%%%%%SAMPLE BEGINS

\version "2.8.6"

example = \relative c'' {
 a4 b c d
 }

 \score {
 \new Staff \example
 \layout { }

 }

%%%%%SAMPLE ENDS


If I define a command \tempoMark, as explained by Guide in Chapter 4...


%%%%%SAMPLE BEGINS

\version "2.8.6"

tempoMark = #(define-music-function (parser location markp) (string?)
# {
 \once \override Score . RehearsalMark #'self-alignment-X = #left
 \once \override Score . RehearsalMark #'no-spacing-rods = ##t
 \mark \markup { \bold $markp }
#})

example = \relative c'' {
 \tempoMark "Allegro"
 a4 b c d
 }

 \score {
 \new Staff \example
 \layout { }

 }

%%%%%SAMPLE ENDS

... Lilypond does'nt create either PS file or PDF, although it does'nt
give me error messages. It happens the same if I put tempoMark
definitions in another file and insert \include command in example.ly.

Could someone tell me where is my error in typing?

Thank you.
        Franek