Hi, I don't know if I can explain the problem I'm having. I made a project with 14 chapters. In each of them, there are graphics embedding metapost code. I proceed as follows : I compile each chapter alone with lmtx then I compile the project containing the 14 chapters. I didn't encounter any problems except with a graphic from the last chapter. It is indeed in chapter 14 but not in the project ! I give the code for this graph. Thanks. Fabrice \startMPcode interim linejoin := mitered; interim ahangle := 30; numeric u, pi; pi = 3.141592653589793; u = 1.5cm; vardef graph_of_function (suffix f) (expr xmin, xmax, xsep) = for x = xmin step xsep until xmax: (x, f(x)) .. endfor (xmax, f(xmax)) enddef ; vardef vline (suffix f, g) (expr x) = (x, min(f(x), g(x))) -- (x, max(f(x),g(x))) enddef; vardef area_between_functions (suffix f, g)(expr a, b, xsep) = buildcycle(graph_of_function(f, a, b, xsep), vline(f, g, b), reverse graph_of_function(g, a, b, xsep), reverse vline(f, g, a)) enddef; vardef xaxis (expr xmin, xmax) = (xmin, 0) -- (xmax, 0) enddef ; vardef yaxis (expr ymin, ymax) = (0, ymin) -- (0, ymax) enddef ; xmin:=-pi/2; xmax := 3*pi/2; ymin := -1.5; ymax := 5; vardef f(expr x)= exp(-x)*(-cos(x)+sin(x)+1) enddef; vardef g(expr x)=-exp(-x)*cos(x) enddef; path C_f, C_g; C_f = graph_of_function(f,xmin, xmax, .1); C_g = graph_of_function(g, xmin, xmax, .1); a := xpart(C_f intersectionpoint C_g); b := xpart(reverse C_f intersectionpoint reverse C_g); fill (area_between_functions(f, g, a, b, 0.1)) scaled u withcolor 0.4[white, blue]; draw C_f scaled u withcolor blue; draw C_g scaled u withcolor blue; \stopMPcode