input mp-scratch;

beginfig(1);%http://serge.mehl.free.fr/anx/pgcd_diff_scratch.html
  draw QPresse("\opSimple{espace}");
  draw Demander("Donner $a$");
  draw MettreVar("a","\opCap{réponse}");
  draw Demander("Donner $b$");
  draw MettreVar("b","\opCap{réponse}");
  draw Si1("\opOp{$\opVar{$a$}=\opVar{$b$}$}");
  draw MettreVar("pgcd","\opVar{$a$}");
  draw Sinon1;
  draw MettreVar("x","\opVar{$a$}");
  draw MettreVar("y","\opVar{$b$}");
  draw MettreVar("r","de \opOp{abs de $\opVar{$a$}-\opVar{$b$}$}");%"\opOp{$\abs$}");%
  draw RepeterJ2("\opOp{$\opVar{$r$}=0$}");
  draw MettreVar("x","\opVar{$a$}");
  draw MettreVar("y","\opVar{$b$}");
  draw MettreVar("pgcd","\opVar{$r$}");
  draw MettreVar("r","de \opOp{abs de $\opVar{$a$}-\opVar{$b$}$}");%"\opOp{$\abs$}");%
  draw FinBlocRepeter2(10);
  draw FinBlocSi1;
endfig;
end