commit ef91426863727b643a44a4122f266b4d878989b1
Author: Yann Esposito (Yogsototh) <Yann.Esposito@gmail.com>
Date:   Tue Oct 1 13:17:56 2013 +0200

    initial commit

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..12d9aab
--- /dev/null
+++ b/README.md
@@ -0,0 +1,47 @@
+# Generate graph in PNG using metapost
+
+First you need to install `metapost` and `imagemagick`.
+
+Then this code provide a nice code to draw graphs and automata.
+Furthermore the script `gen` generate only PNG optimized for the web.
+
+## Example
+
+~~~
+z0=(1.3u,0);
+z1=z0 shifted (u,0);
+z2=z1 shifted (u,0);
+
+nodesize:=4bp;
+nodespace:=6bp;
+
+drawstate(z0);
+drawstate(z1);
+drawstate(z2);
+
+drawarrow edge(z0,z1);
+drawarrow edge(z1,z2);
+drawarrow edgeAngle(z0,z2,-35);
+
+nodesize:=6bp;
+ahlength:=.3nodesize;
+drawarrow edge(z0,z0);
+drawarrow edge(z1,z1);
+drawarrow edge(z2,z2);
+
+label(btex $ = 3 = $ etex,origin);
+drawstate((-1.5u,.2u));
+drawstate((-1.5u-.2u,-.2u));
+drawstate((-1.5u+.2u,-.2u));
+~~~
+
+Render as
+
+<figure>
+<img src="./abstraction.png" alt="The category for the number 3">
+<figcaption>
+The category corresponding to number 3.
+</figcaption>
+</figure>
+
+
diff --git a/abstraction.png b/abstraction.png
new file mode 100644
index 0000000..5673e4d
Binary files /dev/null and b/abstraction.png differ
diff --git a/clean b/clean
new file mode 100755
index 0000000..d60abea
--- /dev/null
+++ b/clean
@@ -0,0 +1,5 @@
+#!/usr/bin/env zsh
+
+listfic=( *.png(N.) )
+((${#listfic} > 0)) && \rm -f $listfic
+[[ -e /tmp/mp ]] && \rm -rf /tmp/mp
diff --git a/examples/README.md b/examples/README.md
new file mode 100644
index 0000000..1839e7e
--- /dev/null
+++ b/examples/README.md
@@ -0,0 +1,3 @@
+# Examples
+
+Put the mp file in the upper directory then just run `./gen` in the upper directory.
diff --git a/examples/abstraction.mp b/examples/abstraction.mp
new file mode 100644
index 0000000..4cb255f
--- /dev/null
+++ b/examples/abstraction.mp
@@ -0,0 +1,25 @@
+z0=(1.3u,0);
+z1=z0 shifted (u,0);
+z2=z1 shifted (u,0);
+
+nodesize:=4bp;
+nodespace:=6bp;
+
+drawstate(z0);
+drawstate(z1);
+drawstate(z2);
+
+drawarrow edge(z0,z1);
+drawarrow edge(z1,z2);
+drawarrow edgeAngle(z0,z2,-35);
+
+nodesize:=6bp;
+ahlength:=.3nodesize;
+drawarrow edge(z0,z0);
+drawarrow edge(z1,z1);
+drawarrow edge(z2,z2);
+
+label(btex $ = 3 = $ etex,origin);
+drawstate((-1.5u,.2u));
+drawstate((-1.5u-.2u,-.2u));
+drawstate((-1.5u+.2u,-.2u));
diff --git a/examples/associativecomposition.mp b/examples/associativecomposition.mp
new file mode 100644
index 0000000..da1c659
--- /dev/null
+++ b/examples/associativecomposition.mp
@@ -0,0 +1,22 @@
+z0=origin;
+z1=(gu,0);
+z2=(2gu,0);
+z3=(3gu,0);
+
+drawState(z0,"A");
+drawState(z1,"B");
+drawState(z2,"C");
+drawState(z3,"D");
+
+drawEdge(z1,z2,"g");
+
+drawoptions(withcolor blue);
+drawEdgeAngle(z0,z2,"g\circ f",35);
+drawEdge(z2,z3,"h");
+
+drawoptions(withcolor green);
+drawEdge(z0,z1,"f");
+drawEdgeAngle(z1,z3,"h\circ g",-35);
+
+drawoptions(withcolor yellow);
+drawEdgeAngle(z0,z3,"(h\circ g)\circ f = h\circ (g\circ f)",50);
diff --git a/examples/boxfunctor.mp b/examples/boxfunctor.mp
new file mode 100644
index 0000000..fe535e3
--- /dev/null
+++ b/examples/boxfunctor.mp
@@ -0,0 +1,43 @@
+pair a,b;
+a:=origin;
+b:=a shifted (1.7gu,0);
+
+drawState(a,"a");
+drawState(b,"b");
+drawEdge(a,b,"f");
+
+pair fa,fb;
+fa=a shifted (0,-.6gu);
+fb=b shifted (0,-.6gu);
+
+drawbox(fa,"F");
+drawState(fa,"a");
+drawbox(fb,"F");
+drawState(fb,"b");
+
+pair mf,mff;
+path ab,fafb;
+ab  :=edge(a,b);
+fafb:=edge(fa,fb);
+mf := midpoint(ab);
+mff := midpoint(fafb);
+path p, arr;
+p := mf -- mff;
+arr := subpath (0.05,0.65) of p;
+drawoptions(withcolor yellow);
+label.rt(btex $\mathtt{fmap}$ etex,midpoint(arr));
+drawoptions(withcolor yellow withpen pencircle scaled 1 dashed evenly);
+drawarrow arr;
+p:=edge(a,fa);
+arr := subpath (0,0.7) of p;
+drawarrow arr;
+label.rt(btex $F$ etex,midpoint(arr));
+p:=edge(b,fb);
+arr := subpath (0,0.7) of p;
+drawarrow arr;
+label.rt(btex $F$ etex,midpoint(arr));
+drawoptions(withcolor base1 dashed evenly);
+drawEdgeAngle(fa,fb,"f",-35);
+nodespace:=2u+1mm;
+drawoptions(withcolor base1);
+drawEdge(fa,fb,"\mathtt{fmap}\ f");
diff --git a/examples/cat-example1.mp b/examples/cat-example1.mp
new file mode 100644
index 0000000..7adf8bd
--- /dev/null
+++ b/examples/cat-example1.mp
@@ -0,0 +1,21 @@
+z0=(0,0);
+z1=2(u,0);
+z2=2(2u,0);
+
+nodesize:=4bp;
+nodespace:=6bp;
+
+drawarrow edge(z0,z1);
+drawarrow edge(z1,z2);
+drawarrow edgeAngle(z0,z2,35);
+
+drawstate(z0);
+drawstate(z1);
+drawstate(z2);
+
+nodesize:=6bp;
+ahlength:=.3nodesize;
+drawarrow edge(z0,z0);
+drawarrow edge(z1,z1);
+drawarrow edge(z2,z2);
+
diff --git a/examples/cat-example2.mp b/examples/cat-example2.mp
new file mode 100644
index 0000000..1b9aeec
--- /dev/null
+++ b/examples/cat-example2.mp
@@ -0,0 +1,13 @@
+z0=(0,0); z1=3(u,0); z2=3(2u,0);
+nodesize:=4bp;
+nodespace:=6bp;
+drawstate(z0); drawstate(z1); drawstate(z2);
+
+drawEdge(z0,z1,"f");
+drawEdge(z1,z2,"g");
+
+nodesize:=6bp;
+ahlength:=.3nodesize;
+drawarrow edge(z0,z0);
+drawarrow edge(z1,z1);
+drawarrow edge(z2,z2);
diff --git a/examples/cat-example3.mp b/examples/cat-example3.mp
new file mode 100644
index 0000000..1d1b2c8
--- /dev/null
+++ b/examples/cat-example3.mp
@@ -0,0 +1,17 @@
+z0=(0,0); z1=(4u,0); z2=(2u,-3u);
+nodesize:=4bp;
+nodespace:=6bp;
+
+drawarrow edgeAngle(z0,z1,35);
+drawarrow edgeAngle(z1,z0,35);
+drawarrow edgeAngle(z1,z2,35);
+drawarrow edgeAngle(z0,z2,-35);
+drawstate(z0);
+drawstate(z1);
+drawstate(z2);
+
+nodesize:=6bp;
+ahlength:=.3nodesize;
+drawarrow edge(z0,z0);
+drawarrow edge(z1,z1);
+drawarrow edge(z2,z2);
diff --git a/examples/cat-example4.mp b/examples/cat-example4.mp
new file mode 100644
index 0000000..af4c36b
--- /dev/null
+++ b/examples/cat-example4.mp
@@ -0,0 +1,12 @@
+z0=(0,0); z1=(gu,0); z2=(.5gu,-.75gu);
+drawState(z0,"A");
+drawState(z1,"B");
+drawState(z2,"C");
+
+drawarrow edgeAngle(z0,z1,35);
+drawarrow edgeAngle(z1,z0,35);
+drawarrow edgeAngle(z1,z2,35);
+drawarrow edgeAngle(z2,z0,35);
+drawarrow edge(z0,z0);
+drawarrow edge(z1,z1);
+drawarrow edge(z2,z2);
diff --git a/examples/cat-example5.mp b/examples/cat-example5.mp
new file mode 100644
index 0000000..35d47c8
--- /dev/null
+++ b/examples/cat-example5.mp
@@ -0,0 +1,10 @@
+z0=origin;
+z1=(gu,0);
+
+drawState(z0,"A");
+drawState(z1,"B");
+drawEdgeAngle(z0,z1,"f",35);
+drawEdge(z1,z0,"g");
+drawEdgeAngle(z0,z1,"h",-35);
+drawEdge(z0,z0,"id_A");
+drawEdge(z1,z1,"id_B");
diff --git a/examples/cat-hask-endofunctor.mp b/examples/cat-hask-endofunctor.mp
new file mode 100644
index 0000000..c799041
--- /dev/null
+++ b/examples/cat-hask-endofunctor.mp
@@ -0,0 +1,108 @@
+% DPI 180
+pair int,bool,func,intlist,list;
+resize(.8cm);
+int=origin;
+% drawoptions (withcolor baseOne withpen pencircle scaled 1.2);
+
+intlist=int shifted (gu,0);
+func=int shifted (0,-.6gu);
+bool=func shifted (gu,0);
+list=func shifted (2u,0);
+
+
+drawLoopPoint(int,int shifted (0,1.6u),"\mathtt{sqrt}");
+drawEdge(int,int,"\mathtt{id}");
+drawEdgeAngle(int,bool,"\mathtt{odd}",-30);
+drawEdgeAngle(int,bool,"\mathtt{even}",30);
+drawEdge(intlist,intlist,"\mathtt{tail}");
+drawEdge(intlist,int,"\mathtt{length}");
+
+% ---------- F ----------------
+
+pair decal;
+pair fint,fbool,ffunc,fintlist,flist;
+decal := (-1.2gu,-1.5gu);
+fint=int shifted decal;
+fintlist=intlist shifted decal;
+ffunc=   func shifted decal;
+fbool=   bool shifted decal;
+flist=   list shifted decal;
+
+drawLoopPoint(fint,fint shifted (0,1.9u),"\scriptstyle\mathtt{fmap\ sqrt}");
+drawEdge(fint,fint,"\scriptstyle\mathtt{fmap\ id}");
+drawEdgeAngle(fint,fbool,"\scriptstyle\mathtt{fmap\ odd}",-30);
+drawEdgeAngle(fint,fbool,"\scriptstyle\mathtt{fmap\ even}",30);
+drawEdge(fintlist,fintlist,"\scriptstyle\mathtt{fmap\ tail}");
+drawEdge(fintlist,fint,"\scriptstyle\mathtt{fmap\ length}");
+
+drawblock(fint,fbool,"\mathtt{F}");
+
+pair ff;
+ff = .5[fint,fintlist] shifted (0,u);
+path b;
+b := block(origin,origin);
+draw b scaled .5 shifted ff;
+label.top(btex $\mathtt{F\ F}$ etex, blockLabelPosition(b)) scaled .5 shifted ff;
+draw b scaled .25 shifted ff;
+label.top(btex $\mathtt{F\ F\ F}$ etex, blockLabelPosition(b)) scaled .25 shifted ff;
+
+% ------------ G --------------
+pair gdecal;
+pair gint,gbool,gfunc,gintlist,glist;
+gdecal := (1.2gu,-1.5gu);
+gint=int shifted gdecal;
+gintlist=intlist shifted gdecal;
+gfunc=   func shifted gdecal;
+gbool=   bool shifted gdecal;
+glist=   list shifted gdecal;
+
+drawLoopPoint(gint,gint shifted (0,1.9u),"\scriptstyle\mathtt{fmap\ sqrt}");
+drawEdge(gint,gint,"\scriptstyle\mathtt{fmap\ id}");
+drawEdgeAngle(gint,gbool,"\scriptstyle\mathtt{fmap\ odd}",-30);
+drawEdgeAngle(gint,gbool,"\scriptstyle\mathtt{fmap\ even}",30);
+drawEdge(gintlist,gintlist,"\scriptstyle\mathtt{fmap\ tail}");
+drawEdge(gintlist,gint,"\scriptstyle\mathtt{fmap\ length}");
+
+drawblock(gint,gbool,"\mathtt{G}");
+
+pair gf;
+gf = .5[gint,gintlist] shifted (0,u);
+path b;
+b := block(origin,origin);
+draw b scaled .5 shifted gf;
+label.top(btex $\mathtt{G\ G}$ etex, blockLabelPosition(b)) scaled .5 shifted gf;
+draw b scaled .25 shifted gf;
+label.top(btex $\mathtt{G\ G\ G}$ etex, blockLabelPosition(b)) scaled .25 shifted gf;
+
+
+drawState(int,"\mathtt{Int}");
+drawState(intlist,"\mathtt{[Int]}");
+drawState(func,"\mathtt{a\rightarrow b}");
+drawState(list,"\mathtt{[a]}");
+drawState(bool,"\mathtt{Bool}");
+
+drawState(fint,"\mathtt{F\ Int}");
+drawState(fintlist,"\mathtt{F\ [Int]}");
+drawState(ffunc,"\mathtt{F\ a\rightarrow b}");
+drawState(flist,"\mathtt{F\ [a]}");
+drawState(fbool,"\mathtt{F\ Bool}");
+
+drawState(gint,"\mathtt{G\ Int}");
+drawState(gintlist,"\mathtt{G\ [Int]}");
+drawState(gfunc,"\mathtt{G\ a\rightarrow b}");
+drawState(glist,"\mathtt{G\ [a]}");
+drawState(gbool,"\mathtt{G\ Bool}");
+
+drawoptions(withcolor yellow);
+label.top(btex $I$ etex, .5[int,intlist] shifted (0,u));
+
+drawoptions(withpen pencircle scaled 2bp withcolor yellow);
+ahlength:=.3u;
+
+drawEdgeAngle(.5[int,func] shifted (-.5u,0), ff shifted (0,2.2u), "?", -30);
+drawEdgeAngle(ff shifted (-u,2.2u), .5[int,func] shifted (-.5u,u), "?", 30);
+drawEdgeAngle(.5[intlist,bool] shifted (.5u,0), gf shifted (0,2.2u), "?", 30);
+drawEdgeAngle(gf shifted (u,2.2u), .5[intlist,bool] shifted (.5u,u), "?", -30);
+
+drawEdgeAngle(.5[fintlist,fbool] shifted (1.1u,u), .5[gint,gfunc] shifted (-1.1u,u), "?", 30);
+drawEdgeAngle(.5[gint,gfunc] shifted (-1.1u,u), .5[fintlist,fbool] shifted (1.1u,u), "?", 30);
diff --git a/examples/commutative-diagram-assoc.mp b/examples/commutative-diagram-assoc.mp
new file mode 100644
index 0000000..9de3aa7
--- /dev/null
+++ b/examples/commutative-diagram-assoc.mp
@@ -0,0 +1,24 @@
+z0=(0,0);
+z1=(gu,0);
+z2=(0,-gu);
+z3=(gu,-gu);
+
+label("A",z0);
+label("B",z1);
+label("B",z2);
+label("C",z3);
+
+drawEdge(z0,z1,"f");
+
+drawEdge(z1,z2,"g");
+
+path ac,ab;
+drawEdge(z2,z3,"h");
+
+ac:=edge(z1,z3);
+drawarrow ac;
+label.rt(btex $h \circ g$ etex,midpoint(ac));
+
+ab:=edge(z0,z2);
+drawarrow ab;
+label.lft(btex $g \circ f$ etex,midpoint(ab));
diff --git a/examples/commutative-diagram-id.mp b/examples/commutative-diagram-id.mp
new file mode 100644
index 0000000..480454f
--- /dev/null
+++ b/examples/commutative-diagram-id.mp
@@ -0,0 +1,23 @@
+z0=(0,0);
+z1=(gu,0);
+z2=(0,-gu);
+z3=(gu,-gu);
+path ac,ab;
+
+label("A",z0);
+label("A",z1);
+label("B",z2);
+label("B",z3);
+
+drawEdge(z0,z1,"id_A");
+drawEdge(z1,z2,"f");
+ab:=edge(z0,z2);
+drawarrow ab;
+label.lft(btex $f$ etex,midpoint(ab));
+
+drawEdge(z2,z3,"id_B");
+
+ac:=edge(z1,z3);
+drawarrow ac;
+label.rt(btex $f$ etex,midpoint(ac));
+
diff --git a/examples/composition.mp b/examples/composition.mp
new file mode 100644
index 0000000..7608828
--- /dev/null
+++ b/examples/composition.mp
@@ -0,0 +1,27 @@
+
+z0=(0,0);
+z1=z0 shifted (gu,0);
+
+z2=z0 shifted (2gu,0);
+z3=z1 shifted (2gu,0);
+
+z4=(0.5gu,-.5gu);
+z5=(1.5gu,0);
+z6=(2.5gu,-.5gu);
+
+
+drawState(z4, "A");
+drawState(z5, "B");
+drawState(z6, "C");
+
+
+drawoptions(withcolor red);
+drawEdgeAngle(z4,z5, "f",30);
+
+drawoptions(withcolor blue);
+drawEdgeAngle(z5,z6, "g",30);
+
+
+drawoptions(withcolor yellow);
+drawEdgeAngle(z4,z6, "g\circ f", 0);
+
diff --git a/examples/endofunctor.mp b/examples/endofunctor.mp
new file mode 100644
index 0000000..d3b2e37
--- /dev/null
+++ b/examples/endofunctor.mp
@@ -0,0 +1,46 @@
+z0=(0,0);
+z1=(gu,0);
+z2=(.5gu,-.75gu);
+
+z3=z0 shifted (2gu,0);
+z4=z1 shifted (2gu,0);
+z5=z2 shifted (2gu,0);
+
+drawblock(z0,(xpart z1,ypart z2),"\mathcal{C}");
+drawblock(z3,(xpart z4,ypart z5),"\mathcal{C}");
+
+drawoptions(withcolor yellow );
+drawState(z0,"A");
+drawState(z1,"B");
+drawState(z4,"B");
+
+drawoptions(withcolor red );
+drawState(z2,"C");
+drawState(z5,"C");
+
+
+drawoptions(withcolor green );
+drawEdge(z2,z2,"id_C");
+
+
+drawoptions(withcolor magenta );
+drawarrow edgeFull(z1,z2,-90,180);
+drawarrow edgeFull(z0,z2,-90,0);
+drawarrow edgeFull(z4,z5,-90,180);
+
+drawoptions(withcolor blue );
+drawEdge(z0,z0,"id_A");
+drawEdge(z1,z1,"id_B");
+drawEdge(z4,z4,"id_B");
+drawarrow edgeAngle(z0,z1,35);
+drawarrow edgeAngle(z1,z0,35);
+
+drawoptions(withcolor green );
+drawEdge(z5,z5,"id_C");
+
+drawoptions(withcolor base01);
+drawState(z3,"A");
+drawEdge(z3,z3,"id_A");
+drawarrow edgeAngle(z3,z4,35);
+drawarrow edgeAngle(z4,z3,35);
+drawarrow edgeFull(z3,z5,-90,0);
diff --git a/examples/functor-morphism-color.mp b/examples/functor-morphism-color.mp
new file mode 100644
index 0000000..1ae1e7d
--- /dev/null
+++ b/examples/functor-morphism-color.mp
@@ -0,0 +1,37 @@
+z0=(0,0);
+z1=(gu,0);
+z2=(.5gu,-.75gu);
+z3=z0 shifted (2gu,0);
+z4=z3 shifted (0,-.75gu);
+
+drawblock(z0,(xpart z1,ypart z2),"\mathcal{C}");
+drawblock(z3,z4,"\mathcal{D}=\mathbf{F}(\mathcal{C})");
+
+drawoptions(withcolor yellow );
+drawState(z0,"A");
+drawState(z1,"B");
+drawState(z3,"X");
+
+drawoptions(withcolor red );
+drawState(z2,"C");
+drawState(z4,"Y");
+
+
+drawoptions(withcolor green );
+drawEdge(z2,z2,"id_C");
+
+
+drawoptions(withcolor magenta );
+drawarrow edgeFull(z1,z2,-90,180);
+drawarrow edgeFull(z0,z2,-90,0);
+drawarrow edgeFull(z3,z4,-35,35+180);
+
+drawoptions(withcolor blue );
+drawEdge(z0,z0,"id_A");
+drawEdge(z1,z1,"id_B");
+drawarrow edgeAngle(z0,z1,35);
+drawarrow edgeAngle(z1,z0,35);
+drawEdge(z3,z3,"id_X");
+
+drawoptions(withcolor green );
+drawEdge(z4,z4,"id_Y");
diff --git a/examples/functor-morphism.mp b/examples/functor-morphism.mp
new file mode 100644
index 0000000..3caf4b1
--- /dev/null
+++ b/examples/functor-morphism.mp
@@ -0,0 +1,87 @@
+z0=(0,0);
+z1=(gu,0);
+z2=(.5gu,-.75gu);
+z3=z0 shifted (2gu,0);
+z4=z3 shifted (0,-.75gu);
+
+drawblock(z0,(xpart z1,ypart z2),"\mathcal{C}");
+drawblock(z3,z4,"\mathcal{D}=\mathbf{F}(\mathcal{C})");
+
+drawState(z0,"A");
+drawState(z1,"B");
+drawState(z2,"C");
+
+drawState(z4,"Y");
+drawState(z3,"X");
+
+
+drawoptions(withcolor green withpen pencircle scaled 1);
+drawEdge(z2,z2,"id_C");
+
+
+drawoptions(withcolor magenta withpen pencircle scaled 1);
+drawarrow edgeFull(z1,z2,-90,180);
+drawarrow edgeFull(z0,z2,-90,0);
+drawarrow edgeFull(z3,z4,-35,35+180);
+
+drawoptions(withcolor blue withpen pencircle scaled 1);
+drawEdge(z0,z0,"id_A");
+drawEdge(z1,z1,"id_B");
+drawarrow edgeAngle(z0,z1,35);
+drawarrow edgeAngle(z1,z0,35);
+drawEdge(z3,z3,"id_X");
+
+drawoptions(withcolor green withpen pencircle scaled 1);
+drawEdge(z4,z4,"id_Y");
+
+% drawarrow edgeAngle(z0,z3,45);
+% drawarrow edge(z1,z3);
+% drawarrow edge(z2,z4);
+
+path la,lb,lc,lx,ly;
+la := edge(z0,z0);
+lb := edge(z1,z1);
+lc := edge(z2,z2);
+lx := edge(z3,z3);
+ly := edge(z4,z4);
+
+pair ia,ib,ic,ix,iy;
+ia := midpoint( la );
+ib := midpoint( lb );
+ic := midpoint( lc );
+ix := midpoint( lx );
+iy := midpoint( ly );
+
+nodesize:= .5u;
+nodespace:= .5u;
+drawoptions(withcolor blue dashed evenly withpen pencircle scaled 1);
+
+drawarrow edgeAngle(ia,ix,35);
+drawarrow edgeAngle(ib,ix,20);
+
+drawoptions(withcolor green dashed evenly withpen pencircle scaled 1);
+drawarrow edgeAngle(ic,iy,0);
+
+path f,g,h,i;
+f:= edgeAngle(z0,z1,35);
+g:= edgeAngle(z1,z0,35);
+h:= edgeFull(z1,z2,-90,180);
+i:= edgeFull(z0,z2,-90,0);
+
+path k;
+k:= edgeFull(z3,z4,-35,35+180);
+
+pair mf,mg,mh,mi,mk;
+mf := midpoint(f);
+mg := midpoint(g);
+mh := midpoint(h);
+mi := midpoint(i);
+mk := midpoint(k);
+
+
+drawoptions(withcolor blue dashed evenly withpen pencircle scaled 1);
+drawarrow edgeAngle(mf,ix,40);
+drawarrow edgeAngle(mg,ix,-15);
+drawoptions(withcolor magenta dashed evenly withpen pencircle scaled 1);
+drawarrow edgeAngle(mi,mk,30);
+drawarrow edgeAngle(mh,mk,15);
diff --git a/examples/functor.mp b/examples/functor.mp
new file mode 100644
index 0000000..5153a65
--- /dev/null
+++ b/examples/functor.mp
@@ -0,0 +1,34 @@
+z0=(0,0);
+z1=(gu,0);
+z2=(.5gu,-.75gu);
+z3=z0 shifted (2gu,0);
+z4=z3 shifted (0,-.75gu);
+
+drawblock(z0,(xpart z1,ypart z2),"\mathcal{C}");
+drawblock(z3,z4,"\mathcal{D}=\mathbf{F}(\mathcal{C})");
+
+drawEdge(z0,z0,"id_A");
+drawEdge(z1,z1,"id_B");
+drawEdge(z2,z2,"id_C");
+drawarrow edgeAngle(z0,z1,35);
+drawarrow edgeAngle(z1,z0,35);
+drawarrow edgeFull(z1,z2,-90,180);
+drawarrow edgeFull(z0,z2,-90,0);
+
+drawEdge(z3,z3,"id_X");
+drawEdge(z4,z4,"id_Y");
+drawarrow edgeFull(z3,z4,-35,35+180);
+
+drawoptions(withcolor yellow withpen pencircle scaled 1);
+drawState(z0,"A");
+drawState(z1,"B");
+drawState(z3,"X");
+drawoptions(withcolor yellow withpen pencircle scaled 1 dashed evenly);
+drawarrow edgeAngle(z0,z3,45);
+drawarrow edge(z1,z3);
+
+drawoptions(withcolor red withpen pencircle scaled 1);
+drawState(z2,"C");
+drawState(z4,"Y");
+drawoptions(withcolor red withpen pencircle scaled 1 dashed evenly);
+drawarrow edge(z2,z4);
diff --git a/examples/graph-category.mp b/examples/graph-category.mp
new file mode 100644
index 0000000..5aa4591
--- /dev/null
+++ b/examples/graph-category.mp
@@ -0,0 +1,11 @@
+pair a,b,c;
+a=origin;
+b=a shifted (gu,0);
+c=a shifted (gu,0) rotated -60;
+
+drawState(a,"X");
+drawState(b,"Y");
+drawState(c,"Z");
+drawEdgeAngle(a,b,"\alpha",30);
+drawEdgeAngle(b,c,"\beta",30);
+drawEdgeAngle(c,a,"\gamma",30);
diff --git a/examples/hask-endofunctor-morphisms.mp b/examples/hask-endofunctor-morphisms.mp
new file mode 100644
index 0000000..647952a
--- /dev/null
+++ b/examples/hask-endofunctor-morphisms.mp
@@ -0,0 +1,103 @@
+pair int,bool,func,intlist,list;
+resize(.8cm);
+int=origin;
+% drawoptions (withcolor baseOne withpen pencircle scaled 1.2);
+
+intlist=int shifted (gu,0);
+func=int shifted (0,-.6gu);
+bool=func shifted (gu,0);
+list=func shifted (2u,0);
+
+
+
+pair decal;
+pair fint,fbool,ffunc,fintlist,flist;
+decal := (1.7gu,0);
+fint=int shifted decal;
+fintlist=intlist shifted decal;
+ffunc=   func shifted decal;
+fbool=   bool shifted decal;
+flist=   list shifted decal;
+
+drawoptions(withcolor yellow withpen pencircle scaled 1);
+drawLoopPoint(int,int shifted (0,1.6u),"\mathtt{sqrt}");
+drawLoopPoint(fint,fint shifted (0,1.9u),"\scriptstyle\mathtt{fmap\ sqrt}");
+
+drawoptions(withcolor green withpen pencircle scaled 1);
+drawEdge(int,int,"\mathtt{id}");
+drawEdge(fint,fint,"\scriptstyle\mathtt{fmap\ id}");
+
+drawoptions(withcolor red withpen pencircle scaled 1);
+drawEdgeAngle(int,bool,"\mathtt{odd}",-30);
+drawEdgeAngle(fint,fbool,"\scriptstyle\mathtt{fmap\ odd}",-30);
+
+drawoptions(withcolor magenta withpen pencircle scaled 1);
+drawEdgeAngle(int,bool,"\mathtt{even}",30);
+drawEdgeAngle(fint,fbool,"\scriptstyle\mathtt{fmap\ even}",30);
+
+drawoptions(withcolor violet withpen pencircle scaled 1);
+drawEdge(intlist,intlist,"\mathtt{tail}");
+drawEdge(fintlist,fintlist,"\scriptstyle\mathtt{fmap\ tail}");
+
+drawoptions(withcolor blue withpen pencircle scaled 1);
+drawEdge(intlist,int,"\mathtt{length}");
+drawEdge(fintlist,fint,"\scriptstyle\mathtt{fmap\ length}");
+
+drawoptions(withcolor base1);
+drawState(int,"\mathtt{Int}");
+drawState(fint,"\mathtt{F\ Int}");
+drawState(intlist,"\mathtt{[Int]}");
+drawState(fintlist,"\mathtt{F\ [Int]}");
+drawState(func,"\mathtt{a\rightarrow b}");
+drawState(ffunc,"\mathtt{F\ a\rightarrow b}");
+drawState(list,"\mathtt{[a]}");
+drawState(flist,"\mathtt{F\ [a]}");
+drawState(bool,"\mathtt{Bool}");
+drawState(fbool,"\mathtt{F\ Bool}");
+
+drawblock(fint,fbool,"\mathtt{F}");
+
+% Draw blocks
+pair ff;
+ff = .5[fint,fintlist] shifted (0,u);
+path b;
+b := block(origin,origin);
+draw b scaled .5 shifted ff;
+label.top(btex $\mathtt{F\ F}$ etex, blockLabelPosition(b)) scaled .5 shifted ff;
+draw b scaled .25 shifted ff;
+label.top(btex $\mathtt{F\ F\ F}$ etex, blockLabelPosition(b)) scaled .25 shifted ff;
+
+pair psqrt,pid,plength,podd,peven,ptail;
+pair pfsqrt,pfid,pflength,pfodd,pfeven,pftail;
+
+psqrt := midpoint(loopPoint(int,int shifted (0,1.6u)));
+pid   := midpoint(edge(int,int));
+podd  := midpoint(edgeAngle(int,bool,-30));
+peven := midpoint(edgeAngle(int,bool,30));
+ptail := midpoint(edge(intlist,intlist));
+plength := midpoint(edge(intlist,int));
+pfsqrt := midpoint(loopPoint(fint,fint shifted (0,1.9u)));
+pfid   := midpoint(edge(fint,fint));
+pfodd  := midpoint(edgeAngle(fint,fbool,-30));
+pfeven := midpoint(edgeAngle(fint,fbool,30));
+pftail := midpoint(edge(fintlist,fintlist));
+pflength := midpoint(edge(fintlist,fint));
+
+nodespace := 6bp;
+drawoptions(withcolor yellow withpen pencircle scaled 1);
+drawarrow edgeAngle(psqrt,pfsqrt,20) dashed evenly;
+
+drawoptions(withcolor green withpen pencircle scaled 1);
+drawarrow edgeAngle(pid,pfid,20) dashed evenly;
+
+drawoptions(withcolor blue withpen pencircle scaled 1);
+drawarrow edgeAngle(plength,pflength,-20) dashed evenly;
+
+drawoptions(withcolor red withpen pencircle scaled 1);
+drawarrow edgeAngle(podd,pfodd,0) dashed evenly;
+
+drawoptions(withcolor magenta withpen pencircle scaled 1);
+drawarrow edgeAngle(peven,pfeven,-20) dashed evenly;
+
+drawoptions(withcolor violet withpen pencircle scaled 1);
+drawarrow edgeAngle(ptail,pftail,-5) dashed evenly;
diff --git a/examples/hask-endofunctor-objects.mp b/examples/hask-endofunctor-objects.mp
new file mode 100644
index 0000000..9bbbac8
--- /dev/null
+++ b/examples/hask-endofunctor-objects.mp
@@ -0,0 +1,70 @@
+pair int,bool,func,intlist,list;
+resize(.8cm);
+int=origin;
+% drawoptions (withcolor baseOne withpen pencircle scaled 1.2);
+
+intlist=int shifted (gu,0);
+func=int shifted (0,-.6gu);
+bool=func shifted (gu,0);
+list=func shifted (2u,0);
+
+
+drawLoopPoint(int,int shifted (0,1.6u),"\mathtt{sqrt}");
+drawEdge(int,int,"\mathtt{id}");
+drawEdgeAngle(int,bool,"\mathtt{odd}",-30);
+drawEdgeAngle(int,bool,"\mathtt{even}",30);
+drawEdge(intlist,intlist,"\mathtt{tail}");
+drawEdge(intlist,int,"\mathtt{length}");
+
+pair decal;
+pair fint,fbool,ffunc,fintlist,flist;
+decal := (1.7gu,0);
+fint=int shifted decal;
+fintlist=intlist shifted decal;
+ffunc=   func shifted decal;
+fbool=   bool shifted decal;
+flist=   list shifted decal;
+
+drawLoopPoint(fint,fint shifted (0,1.9u),"\scriptstyle\mathtt{fmap\ sqrt}");
+drawEdge(fint,fint,"\scriptstyle\mathtt{fmap\ id}");
+drawEdgeAngle(fint,fbool,"\scriptstyle\mathtt{fmap\ odd}",-30);
+drawEdgeAngle(fint,fbool,"\scriptstyle\mathtt{fmap\ even}",30);
+drawEdge(fintlist,fintlist,"\scriptstyle\mathtt{fmap\ tail}");
+drawEdge(fintlist,fint,"\scriptstyle\mathtt{fmap\ length}");
+
+
+drawblock(fint,fbool,"\mathtt{F}");
+
+pair ff;
+ff = .5[fint,fintlist] shifted (0,u);
+path b;
+b := block(origin,origin);
+draw b scaled .5 shifted ff;
+label.top(btex $\mathtt{F\ F}$ etex, blockLabelPosition(b)) scaled .5 shifted ff;
+draw b scaled .25 shifted ff;
+label.top(btex $\mathtt{F\ F\ F}$ etex, blockLabelPosition(b)) scaled .25 shifted ff;
+
+drawoptions(withcolor yellow withpen pencircle scaled 1);
+drawarrow edgeAngle(int,fint,45) dashed evenly;
+drawState(int,"\mathtt{Int}");
+drawState(fint,"\mathtt{F\ Int}");
+
+drawoptions(withcolor green withpen pencircle scaled 1);
+drawarrow edgeAngle(intlist,fintlist,-20) dashed evenly;
+drawState(intlist,"\mathtt{[Int]}");
+drawState(fintlist,"\mathtt{F\ [Int]}");
+
+drawoptions(withcolor blue withpen pencircle scaled 1);
+drawarrow edgeAngle(func,ffunc,-20) dashed evenly;
+drawState(func,"\mathtt{a\rightarrow b}");
+drawState(ffunc,"\mathtt{F\ a\rightarrow b}");
+
+drawoptions(withcolor red withpen pencircle scaled 1);
+drawarrow edgeAngle(list,flist,25) dashed evenly;
+drawState(list,"\mathtt{[a]}");
+drawState(flist,"\mathtt{F\ [a]}");
+
+drawoptions(withcolor magenta withpen pencircle scaled 1);
+drawarrow edgeAngle(bool,fbool,-20) dashed evenly;
+drawState(bool,"\mathtt{Bool}");
+drawState(fbool,"\mathtt{F\ Bool}");
diff --git a/examples/hask-endofunctor.mp b/examples/hask-endofunctor.mp
new file mode 100644
index 0000000..1199f8c
--- /dev/null
+++ b/examples/hask-endofunctor.mp
@@ -0,0 +1,56 @@
+pair int,bool,func,intlist,list;
+resize(.8cm);
+int=origin;
+% drawoptions (withcolor baseOne withpen pencircle scaled 1.2);
+
+intlist=int shifted (gu,0);
+func=int shifted (0,-.6gu);
+bool=func shifted (gu,0);
+list=func shifted (2u,0);
+
+
+drawLoopPoint(int,int shifted (0,1.6u),"\mathtt{sqrt}");
+drawEdge(int,int,"\mathtt{id}");
+drawEdgeAngle(int,bool,"\mathtt{odd}",-30);
+drawEdgeAngle(int,bool,"\mathtt{even}",30);
+drawEdge(intlist,intlist,"\mathtt{tail}");
+drawEdge(intlist,int,"\mathtt{length}");
+
+pair decal;
+pair fint,fbool,ffunc,fintlist,flist;
+decal := (1.7gu,0);
+fint=int shifted decal;
+fintlist=intlist shifted decal;
+ffunc=   func shifted decal;
+fbool=   bool shifted decal;
+flist=   list shifted decal;
+
+
+drawLoopPoint(fint,fint shifted (0,1.9u),"\scriptstyle\mathtt{fmap\ sqrt}");
+drawEdge(fint,fint,"\scriptstyle\mathtt{fmap\ id}");
+drawEdgeAngle(fint,fbool,"\scriptstyle\mathtt{fmap\ odd}",-30);
+drawEdgeAngle(fint,fbool,"\scriptstyle\mathtt{fmap\ even}",30);
+drawEdge(fintlist,fintlist,"\scriptstyle\mathtt{fmap\ tail}");
+drawEdge(fintlist,fint,"\scriptstyle\mathtt{fmap\ length}");
+
+drawblock(fint,fbool,"\mathtt{F}");
+
+pair ff;
+ff = .5[fint,fintlist] shifted (0,u);
+path b;
+b := block(origin,origin);
+draw b scaled .5 shifted ff;
+label.top(btex $\mathtt{F\ F}$ etex, blockLabelPosition(b)) scaled .5 shifted ff;
+draw b scaled .25 shifted ff;
+label.top(btex $\mathtt{F\ F\ F}$ etex, blockLabelPosition(b)) scaled .25 shifted ff;
+
+drawState(int,"\mathtt{Int}");
+drawState(fint,"\mathtt{F\ Int}");
+drawState(intlist,"\mathtt{[Int]}");
+drawState(fintlist,"\mathtt{F\ [Int]}");
+drawState(func,"\mathtt{a\rightarrow b}");
+drawState(ffunc,"\mathtt{F\ a\rightarrow b}");
+drawState(list,"\mathtt{[a]}");
+drawState(flist,"\mathtt{F\ [a]}");
+drawState(bool,"\mathtt{Bool}");
+drawState(fbool,"\mathtt{F\ Bool}");
diff --git a/examples/hask.mp b/examples/hask.mp
new file mode 100644
index 0000000..301399d
--- /dev/null
+++ b/examples/hask.mp
@@ -0,0 +1,22 @@
+pair int,bool,func,intlist,list;
+resize(.8cm);
+int=origin;
+% drawoptions (withcolor baseOne withpen pencircle scaled 1.2);
+
+intlist=int shifted (gu,0);
+func=int shifted (0,-.6gu);
+bool=func shifted (gu,0);
+list=func shifted (2u,0);
+
+drawState(int,"\mathtt{Int}");
+drawState(bool,"\mathtt{Bool}");
+drawState(func,"\mathtt{a\rightarrow b}");
+drawState(intlist,"\mathtt{[Int]}");
+drawState(list,"\mathtt{[a]}");
+
+drawLoopPoint(int,int shifted (0,1.6u),"\mathtt{sqrt}");
+drawEdge(int,int,"\mathtt{id}");
+drawEdgeAngle(int,bool,"\mathtt{odd}",-30);
+drawEdgeAngle(int,bool,"\mathtt{even}",30);
+drawEdge(intlist,intlist,"\mathtt{tail}");
+drawEdge(intlist,int,"\mathtt{length}");
diff --git a/examples/identity.mp b/examples/identity.mp
new file mode 100644
index 0000000..d25e00c
--- /dev/null
+++ b/examples/identity.mp
@@ -0,0 +1,11 @@
+
+z0=(0,0);
+z1=z0 shifted (2gu,0);
+
+drawState(z0, "A");
+drawState(z1, "B");
+
+drawoptions(withcolor yellow);
+drawEdge(z0,z1, "id_B\circ f = f = f \circ id_A");
+drawEdge(z0,z0, "id_A");
+drawEdge(z1,z1, "id_B");
diff --git a/examples/list-maybe-endofunctor-morphism.mp b/examples/list-maybe-endofunctor-morphism.mp
new file mode 100644
index 0000000..c0b21d7
--- /dev/null
+++ b/examples/list-maybe-endofunctor-morphism.mp
@@ -0,0 +1,8 @@
+pair tree,list;
+resize(.8cm);
+
+list=origin;
+tree=list shifted (gu,0);
+drawState(list,"\mathtt{[]}");
+drawState(tree,"\mathtt{Maybe}");
+drawEdgeAngle(list,tree,"\mathtt{toMaybe}",30);
diff --git a/examples/list-tree-endofunctor-morphism.mp b/examples/list-tree-endofunctor-morphism.mp
new file mode 100644
index 0000000..33725e1
--- /dev/null
+++ b/examples/list-tree-endofunctor-morphism.mp
@@ -0,0 +1,7 @@
+pair tree,list;
+resize(.8cm);
+list=origin;
+tree=list shifted (gu,0);
+drawState(list,"\mathtt{[]}");
+drawState(tree,"\mathtt{List}");
+drawEdgeAngle(list,tree,"\mathtt{toList}",30);
diff --git a/examples/maybe-list-endofunctor-morphsm.mp b/examples/maybe-list-endofunctor-morphsm.mp
new file mode 100644
index 0000000..bd302c1
--- /dev/null
+++ b/examples/maybe-list-endofunctor-morphsm.mp
@@ -0,0 +1,9 @@
+pair tree,list;
+resize(.8cm);
+list=origin;
+
+tree=list shifted (gu,0);
+drawState(list,"\mathtt{[]}");
+drawState(tree,"\mathtt{Maybe}");
+drawEdgeAngle(list,tree,"\mathtt{toMaybe}",30);
+drawEdgeAngle(tree,list,"\mathtt{mToList}",30);
diff --git a/examples/monoid.mp b/examples/monoid.mp
new file mode 100644
index 0000000..47e63f1
--- /dev/null
+++ b/examples/monoid.mp
@@ -0,0 +1,14 @@
+pair A,B,C,D,E,F;
+A:=(0,0); B:=(0,u); C:=(0,2u);
+D:=(0,3u); E:=(0,4u); F:=(0,6u);
+
+nodesize:=4bp;
+nodespace:=6bp;
+
+drawLoopPoint(A,B,"\varepsilon");
+drawLoopPoint(A,C,"a");
+drawLoopPoint(A,D,"b");
+drawLoopPoint(A,E,"ab");
+drawLoopPoint(A,F,"\omega");
+draw (0,4.8u)--(0,5.8u) dashed withdots;
+draw A withpen pencircle scaled 4bp;
diff --git a/examples/morphisms.mp b/examples/morphisms.mp
new file mode 100644
index 0000000..f9574e4
--- /dev/null
+++ b/examples/morphisms.mp
@@ -0,0 +1,46 @@
+
+z0=(0,0);
+z1=z0 shifted (gu,0);
+z2=z1 shifted (gu,0);
+z3=z2 shifted (gu,-0.5gu);
+z4=z3 shifted (gu,0);
+z5=z4 shifted (1.5u,0);
+z6=z5 shifted (2u,0);
+
+drawblock(z0,z6,"\mathcal{C}");
+
+drawState(z0, "A");
+drawState(z1, "B");
+drawState(z2, "C");
+
+drawState(z3, "D");
+
+drawoptions(withcolor base01);
+drawarrow loopPoint(z3,z3 shifted (0,3.8u)) dashed evenly;
+drawarrow loopPoint(z3,z3 shifted (0,4u)) dashed evenly;
+drawState(z4, "E");
+drawEdge(z4,z4, "id_E");
+drawarrow edgeAngle(z3,z4,0) dashed evenly;
+drawarrow edgeAngle(z3,z4,20) dashed evenly;
+drawarrow edgeAngle(z3,z4,-20) dashed evenly;
+draw z5 -- z6 dashed withdots withpen pencircle scaled 2bp;
+
+drawoptions(withcolor yellow);
+drawarrow loopPoint(z3,z3 shifted (0,3.5u)) dashed evenly;
+drawEdge(z3,z3, "id_D");
+drawLoopPoint(z3,z3 shifted (0,2.5u),"\ell");
+
+drawEdge(z0,z1, "f");
+drawEdgeAngle(z0,z1, "f'", 45);
+
+drawEdge(z0,z0, "id_A");
+drawEdge(z1,z1, "id_B");
+drawEdge(z2,z2, "id_C");
+
+drawEdgeAngle(z1,z2, "g", 0);
+drawEdgeAngle(z1,z2, "g'", 45);
+
+drawEdgeAngle(z0,z2, "h", -30);
+drawarrow edgeAngle(z0,z2,-45) dashed evenly;
+drawarrow edgeAngle(z0,z2,-55) dashed evenly withcolor base01;
+drawarrow edgeAngle(z0,z2,-60) dashed evenly withcolor base01;
diff --git a/examples/nattrans-list-maybe.mp b/examples/nattrans-list-maybe.mp
new file mode 100644
index 0000000..ed2af14
--- /dev/null
+++ b/examples/nattrans-list-maybe.mp
@@ -0,0 +1,20 @@
+z0=(0,0);
+z1=(1.5gu,0);
+z2=(0,-gu);
+z3=(1.5gu,-gu);
+path ac,ab;
+
+label(btex $\mathtt{[a]}$ etex,z0);
+label(btex $\mathtt{[b]}$ etex,z1);
+label(btex $\mathtt{Maybe\ a}$ etex,z2 shifted (-u,0));
+label(btex $\mathtt{Maybe\ b}$ etex,z3 shifted (u,0));
+
+drawEdge(z0,z1,"\mathtt{fmap_{[]}\ f}");
+drawEdge(z2,z3,"\mathtt{fmap_{Maybe}\ f}");
+ab:=edge(z0,z2);
+drawarrow ab;
+label.lft(btex $\mathtt{toMaybe}$ etex,midpoint(ab));
+
+ac:=edge(z1,z3);
+drawarrow ac;
+label.rt(btex $\mathtt{toMaybe}$ etex,midpoint(ac));
diff --git a/examples/nattrans-list-tree.mp b/examples/nattrans-list-tree.mp
new file mode 100644
index 0000000..ff09e59
--- /dev/null
+++ b/examples/nattrans-list-tree.mp
@@ -0,0 +1,21 @@
+z0=(0,0);
+z1=(1.5gu,0);
+z2=(0,-gu);
+z3=(1.5gu,-gu);
+path ac,ab;
+
+label(btex $\mathtt{[a]}$ etex,z0);
+label(btex $\mathtt{[b]}$ etex,z1);
+label(btex $\mathtt{List\ a}$ etex,z2 shifted (-u,0));
+label(btex $\mathtt{List\ b}$ etex,z3 shifted (u,0));
+
+drawEdge(z0,z1,"\mathtt{fmap_{[]}\ f}");
+drawEdge(z2,z3,"\mathtt{fmap_{List}\ f}");
+ab:=edge(z0,z2);
+drawarrow ab;
+label.lft(btex $\mathtt{toList}$ etex,midpoint(ab));
+
+ac:=edge(z1,z3);
+drawarrow ac;
+label.rt(btex $\mathtt{toList}$ etex,midpoint(ac));
+
diff --git a/examples/nattrans-maybe-list.mp b/examples/nattrans-maybe-list.mp
new file mode 100644
index 0000000..4ffb30a
--- /dev/null
+++ b/examples/nattrans-maybe-list.mp
@@ -0,0 +1,21 @@
+z0=(0,0);
+z1=(1.5gu,0);
+z2=(0,-gu);
+z3=(1.5gu,-gu);
+path ac,ab;
+
+label(btex $\mathtt{[a]}$ etex,z0);
+label(btex $\mathtt{[b]}$ etex,z1);
+label(btex $\mathtt{Maybe\ a}$ etex,z2 shifted (-u,0));
+label(btex $\mathtt{Maybe\ b}$ etex,z3 shifted (u,0));
+
+drawEdge(z0,z1,"\mathtt{fmap_{[]}\ f}");
+drawEdge(z2,z3,"\mathtt{fmap_{Maybe}\ f}");
+
+path abb,acb;
+abb:=edge(z2 shifted (.2u,0),z0 shifted (.2u,0));
+acb:=edge(z3 shifted (-.2u,0),z1 shifted (-.2u,0));
+drawarrow abb;
+drawarrow acb;
+label.rt(btex $\mathtt{mToList}$ etex,midpoint(abb));
+label.lft(btex $\mathtt{mToList}$ etex,midpoint(acb));
diff --git a/examples/nattrans-tree-list.mp b/examples/nattrans-tree-list.mp
new file mode 100644
index 0000000..d2d87e5
--- /dev/null
+++ b/examples/nattrans-tree-list.mp
@@ -0,0 +1,29 @@
+z0=(0,0);
+z1=(1.5gu,0);
+z2=(0,-gu);
+z3=(1.5gu,-gu);
+path ac,ab;
+
+label(btex $\mathtt{[a]}$ etex,z0);
+label(btex $\mathtt{[b]}$ etex,z1);
+label(btex $\mathtt{List\ a}$ etex,z2 shifted (-u,0));
+label(btex $\mathtt{List\ b}$ etex,z3 shifted (u,0));
+
+drawEdge(z0,z1,"\mathtt{fmap_{[]}\ f}");
+drawEdge(z2,z3,"\mathtt{fmap_{List}\ f}");
+ab:=edge(z0,z2);
+drawarrow ab;
+label.lft(btex $\mathtt{toList}$ etex,midpoint(ab));
+
+ac:=edge(z1,z3);
+drawarrow ac;
+label.rt(btex $\mathtt{toList}$ etex,midpoint(ac));
+
+drawoptions(withcolor yellow);
+path abb,acb;
+abb:=edge(z2 shifted (.2u,0),z0 shifted (.2u,0));
+acb:=edge(z3 shifted (-.2u,0),z1 shifted (-.2u,0));
+drawarrow abb;
+drawarrow acb;
+label.rt(btex $\mathtt{toHList}$ etex,midpoint(abb));
+label.lft(btex $\mathtt{toHList}$ etex,midpoint(acb));
diff --git a/examples/natural-transformation.mp b/examples/natural-transformation.mp
new file mode 100644
index 0000000..8ef2add
--- /dev/null
+++ b/examples/natural-transformation.mp
@@ -0,0 +1,21 @@
+z0=(0,0);
+z1=(gu,0);
+z2=(0,-gu);
+z3=(gu,-gu);
+path ac,ab;
+
+label(btex $F X$ etex,z0);
+label(btex $F Y$ etex,z1);
+label(btex $G X$ etex,z2);
+label(btex $G Y$ etex,z3);
+
+drawEdge(z0,z1,"F f");
+drawEdge(z2,z3,"G f");
+ab:=edge(z0,z2);
+drawarrow ab;
+label.lft(btex $\eta_X$ etex,midpoint(ab));
+
+ac:=edge(z1,z3);
+drawarrow ac;
+label.rt(btex $\eta_Y$ etex,midpoint(ac));
+
diff --git a/examples/numbers.mp b/examples/numbers.mp
new file mode 100644
index 0000000..0cf146f
--- /dev/null
+++ b/examples/numbers.mp
@@ -0,0 +1,19 @@
+z0=(0,0);
+drawblock(z0,z0,"0");
+
+z1=(gu,0);
+
+drawblock(z1,z1,"1");
+drawState(z1, "0");
+drawEdge(z1,z1, "id_0");
+
+z2=z1 shifted (gu,0);
+z3=z2 shifted (gu,0);
+
+drawblock(z2,z3,"2");
+
+drawState(z2, "0");
+drawState(z3, "1");
+drawEdge(z2,z2, "id_0");
+drawEdge(z3,z3, "id_1");
+drawarrow edge(z2,z3);
diff --git a/examples/objects.mp b/examples/objects.mp
new file mode 100644
index 0000000..11dfe28
--- /dev/null
+++ b/examples/objects.mp
@@ -0,0 +1,19 @@
+
+z0=(0,0);
+z1=z0 shifted (gu,0);
+z2=z1 shifted (gu,0);
+z3=z2 shifted (gu,-0.5gu);
+z4=z3 shifted (gu,0);
+z5=z4 shifted (1.5u,0);
+z6=z5 shifted (2u,0);
+
+drawblock(z0,z6,"\mathcal{C}");
+draw z5 -- z6 dashed withdots withpen pencircle scaled 2bp;
+
+drawoptions(withcolor yellow);
+drawState(z0, "A");
+drawState(z1, "B");
+drawState(z2, "C");
+
+drawState(z3, "D");
+drawState(z4, "E");
diff --git a/examples/pipe.mp b/examples/pipe.mp
new file mode 100644
index 0000000..08d1bab
--- /dev/null
+++ b/examples/pipe.mp
@@ -0,0 +1,149 @@
+
+vardef inmouthsize(expr pos,size) =
+    fullcircle xscaled 0.6 scaled size shifted pos
+enddef;
+vardef outmouthsize(expr pos,size) =
+    (subpath (0,4) of fullcircle rotated -90) xscaled 0.6 scaled size shifted pos
+enddef;
+vardef hiddenoutmouthsize(expr pos,size) =
+    (subpath (4,8) of fullcircle rotated -90) xscaled 0.6 scaled size shifted pos
+enddef;
+vardef inmouth(expr pos) =
+    inmouthsize(pos,2u)
+enddef;
+vardef outmouth(expr pos) =
+    outmouthsize(pos,2u)
+enddef;
+vardef hiddenoutmouth(expr pos) =
+    hiddenoutmouthsize(pos,2u)
+enddef;
+def drawoutmouth(expr pos) =
+    draw outmouth(pos);
+enddef;
+
+def drawtube(expr pos) =
+    begingroup;
+    save midin,midout;
+    pair midin,midout;
+    midin := pos;
+    midout := pos shifted (gu,0);
+    drawoutmouth(midin);
+    drawoutmouth(midout);
+
+    save topin,topout,botin,botout;
+    pair topin,topout,botin,botout;
+    topin=pos shifted (0,u);
+    topout=topin shifted (gu,0);
+    botin=pos shifted (0,-u);
+    botout=botin shifted (gu,0);
+    draw topin -- topout;
+    draw botin -- botout;
+    endgroup;
+enddef;
+def drawtubelabel(expr pos,l) =
+    drawtube(pos);
+    label(l,pos shifted (.5gu,0));
+enddef;
+def drawtwotubes(expr posintop,posinbot,posout) =
+    begingroup;
+    draw outmouth(posintop);
+    draw outmouth(posinbot);
+    draw outmouth(posout);
+
+    save intopt,intopb,inbott,inbotb,outt,outb;
+    pair intopt,intopb,inbott,inbotb,outt,outb;
+    intopt=posintop shifted (0,u);
+    intopb=posintop shifted (0,-u);
+    inbott=posinbot shifted (0,u);
+    inbotb=posinbot shifted (0,-u);
+    outt=posout shifted (0,u);
+    outb=posout shifted (0,-u);
+
+    draw intopt{right} .. {right}outt;
+    draw intopb{right} .. {left}inbott;
+    draw inbotb{right} .. {right}outb;
+
+    endgroup;
+enddef;
+def drawtwotubeslabel(expr ptop,pbot,pout,l) =
+    begingroup;
+    drawtwotubes(ptop,pbot,pout);
+    save mid;
+    pair mid;
+    mid = 6/30ptop+6/30pbot+18/30pout;
+    label(l,mid);
+    endgroup;
+enddef;
+def drawlongbegintube (expr pos,len) =
+    draw (subpath (4,8) of fullcircle rotated -90) scaled 2u shifted pos shifted (-len,0);
+    draw (pos shifted (-len,u)){right}..{right}(pos shifted (0,u));
+    draw (pos shifted (-len,-u)){right}..{right}(pos shifted (0,-u));
+    draw outmouth(pos);
+enddef;
+def drawbegintube (expr pos) =
+    drawlongbegintube(pos,2u);
+enddef;
+
+def drawbegintubelabel(expr pos,l) =
+    drawbegintube(pos);
+    label(l,pos shifted (-1.5u,0));
+enddef;
+
+def drawtube(expr pos) =
+    begingroup;
+    save midin,midout;
+    pair midin,midout;
+    midin := pos;
+    midout := pos shifted (gu,0);
+    draw outmouth(midin);
+    draw outmouth(midout);
+
+    save topin,topout,botin,botout;
+    pair topin,topout,botin,botout;
+    topin=pos shifted (0,u);
+    topout=topin shifted (gu,0);
+    botin=pos shifted (0,-u);
+    botout=botin shifted (gu,0);
+    draw topin -- topout;
+    draw botin -- botout;
+    endgroup;
+enddef;
+def drawtubelabel(expr pos,l) =
+    drawtube(pos);
+    label(l,pos shifted (.5gu,0));
+enddef;
+
+pair pos;
+pos:=origin;
+z0=(2.5gu,.5gu);
+z1=(0,-1.5gu);
+z2=z1 shifted (3gu,0);
+
+drawbegintubelabel(pos shifted (-.5gu,.5gu),btex $42$ etex);
+drawbegintubelabel(pos shifted (-.5gu,-.5gu),btex $\mathtt{"foo"}$ etex);
+drawtwotubeslabel(pos shifted (0,.5gu), pos shifted (0,-.5gu), pos shifted (gu,0),btex $+$ etex);
+draw inmouth(pos shifted (0,.5gu)  );
+draw inmouth(pos shifted (0,-.5gu) );
+
+drawbegintubelabel(z0 shifted (-2u,-gu),btex $\mathtt{"foo"}$ etex);
+drawoptions(withcolor green);
+drawbegintubelabel(z0,btex $42$ etex);
+drawtwotubeslabel(z0, z0 shifted (0,-gu), z0 shifted (gu,-0.5gu),btex $+$ etex);
+draw inmouth(z0 shifted (0,-gu));
+
+
+drawoptions(withcolor green);
+drawbegintubelabel(z1,btex $\mathtt{"foo"}$ etex);
+drawtubelabel(z1,btex $\mathtt{(+\ 42)}$ etex)
+
+drawoptions(withcolor red);
+drawlongbegintube(z2,5u);
+label(btex $\mathtt{(+\ 42\ "foo")}$ etex,z2 shifted (-3u,0));
+draw z2 shifted (-4u,2u) -- z2 shifted (0,-2u) dashed evenly withpen pencircle scaled 1bp;
+draw z2 shifted (-4u,-2u) -- z2 shifted (0,2u) dashed evenly withpen pencircle scaled 1bp;
+
+drawoptions(withcolor base01);
+drawarrow pos shifted (gu+2u,0) -- pos shifted (gu+4u,0);
+drawarrow z0 shifted (-gu,-gu-u) .. z1 shifted (gu,2u);
+drawarrow pos shifted (gu+u,-1.5gu) -- pos shifted (gu+3u,-1.5gu);
+
diff --git a/examples/preorder.mp b/examples/preorder.mp
new file mode 100644
index 0000000..55ddb90
--- /dev/null
+++ b/examples/preorder.mp
@@ -0,0 +1,20 @@
+pair A,B,C,D;
+A=(0,0);
+B=A shifted (-1.5gu,0);
+C=A shifted (1.5gu,0);
+D=C shifted (1.5gu,0);
+
+drawState(A, "A");
+drawState(B, "B");
+drawState(C, "C");
+drawState(D, "D");
+
+drawEdge(B,A,"A \leq B");
+drawEdge(C,A,"A \leq C");
+drawEdge(D,C,"C \leq D");
+drawEdgeAngle(D,A,"A \leq D", 35);
+
+drawEdge(A,A,"A \leq A");
+drawEdge(B,B,"B \leq B");
+drawEdge(C,C,"C \leq C");
+drawEdge(D,D,"D \leq D");
diff --git a/examples/set.mp b/examples/set.mp
new file mode 100644
index 0000000..382ccb4
--- /dev/null
+++ b/examples/set.mp
@@ -0,0 +1,15 @@
+pair A,B,C,D;
+A=(0,0);
+B=A shifted (.7gu,1/2gu);
+C=A shifted (.7gu,-1/2gu);
+D=C shifted (.7gu,0);
+
+drawState(A, "A");
+drawState(B, "B");
+drawState(C, "C");
+drawState(D, "D");
+
+drawEdge(A,A,"id_A");
+drawEdge(B,B,"id_B");
+drawEdge(C,C,"id_C");
+drawEdge(D,D,"id_D");
diff --git a/examples/strings.mp b/examples/strings.mp
new file mode 100644
index 0000000..6d45dce
--- /dev/null
+++ b/examples/strings.mp
@@ -0,0 +1,12 @@
+pair A,B,C,D,E,F;
+A:=(0,0); B:=(0,u); C:=(0,2u);
+D:=(0,3u); E:=(0,4u); F:=(0,6u);
+nodesize:=4bp;
+nodespace:=6bp;
+drawLoopPoint(A,B,"''");
+drawLoopPoint(A,C,"a");
+drawLoopPoint(A,D,"b");
+drawLoopPoint(A,E,"ab");
+drawLoopPoint(A,F,"\omega");
+draw (0,4.8u)--(0,5.8u) dashed withdots;
+draw A withpen pencircle scaled 4bp;
diff --git a/examples/tree-list-endofunctor-morphism.mp b/examples/tree-list-endofunctor-morphism.mp
new file mode 100644
index 0000000..aa1295c
--- /dev/null
+++ b/examples/tree-list-endofunctor-morphism.mp
@@ -0,0 +1,9 @@
+pair tree,list;
+resize(.8cm);
+list=origin;
+tree=list shifted (gu,0);
+drawState(list,"\mathtt{[]}");
+drawState(tree,"\mathtt{List}");
+drawEdgeAngle(list,tree,"\mathtt{toList}",30);
+drawoptions(withcolor yellow);
+drawEdgeAngle(tree,list,"\mathtt{toHList}",30);
diff --git a/gen b/gen
new file mode 100755
index 0000000..06f1202
--- /dev/null
+++ b/gen
@@ -0,0 +1,76 @@
+#!/usr/bin/env zsh
+
+function err(){ print -- $@ >&2; exit 1 }
+
+# scriptdir is the directory of the current executable
+if [[ ${0[0]} = '/' ]]; then
+    scriptdir="${0:h}"
+else
+    scriptdir="$PWD/${0:h}"
+fi
+
+# the tmp directory where compilation occurs with a lot of temporary files
+tmpdir=/tmp/mp
+[[ ! -d $tmpdir ]] && mkdir $tmpdir
+
+# the list of mp files without argument all file in the current tree
+typeset -a fics
+if (($#<1)); then
+    fics=( $scriptdir/*.mp(N) )
+else
+    for f in $@; fics=( $fics $scriptdir/$f )
+fi
+
+(( ${#fics} == 0 )) && err "No .mp files into $scriptdir"
+
+(( ${#fics} == 1 )) && [[ ${fics[1]} = "$scriptdir/graph.mp" ]] && \
+        err "Only graph.mp files indo $scriptdir"
+
+\cp -f $fics $tmpdir
+cd $tmpdir
+for fpfic in $fics; do
+    fic=${fpfic:t}
+    tmp=${fic:r}-tmp.mp
+    eps=${fic:r}-tmp.1
+    png=${fic:r}.png
+    old=${fic:r}.old
+    [[ $fic = "graph.mp" ]] && continue
+    {
+        echo -n >&2 "MPOST [$fic]"
+        cat $scriptdir/graph.mp
+        echo 'beginfig(1)'
+        echo '  drawoptions (withcolor base01);'
+        cat $fic
+        echo 'endfig;'
+        echo 'bye;'
+    } | sed 's/base00/baseZeroZero/g' \
+      | sed 's/base01/baseZeroOne/g' \
+      | sed 's/base02/baseZeroTwo/g' \
+      | sed 's/base03/baseZeroThree/g' \
+      | sed 's/base0/baseZero/g' \
+      | sed 's/base1/baseOne/g' \
+      | sed 's/base2/baseTwo/g' \
+      | sed 's/base3/baseThree/g' \
+      | sed 's/red/s_red/g' \
+      | sed 's/blue/s_blue/g' \
+      | sed 's/green/s_green/g' > $tmp
+    [[ -e $old ]] && diff $tmp $old >/dev/null && { echo " identical"; continue }
+
+	dpi=$(grep '% DPI' $tmp | awk '{print $3}')
+	[[ $dpi = "" ]] && dpi=600
+
+	print
+	print "[DPI]: $dpi"
+
+    # addshadow="'(' +clone -background black -shadow 90x4+0+1 ')' +swap -background none -layers merge +repage"
+    addshadow=""
+    reducesize=" -colors 254 -quality 75"
+    cmd="convert -colorspace rgb -density $((4*dpi)) $eps -resize 25% $addshadow $reducesize $png"
+
+    print -- "[$PWD]: mpost $tmp && convert -density $dpi $tmp.1 $png"
+    mpost --tex=latex $tmp && \
+        eval $cmd && \
+        \cp -f $png $scriptdir && \
+        \cp -f $tmp $old && \
+        echo "updated"
+done
diff --git a/graph.mp b/graph.mp
new file mode 100644
index 0000000..3ba5584
--- /dev/null
+++ b/graph.mp
@@ -0,0 +1,339 @@
+% solarized color scheme
+color baseZeroThree, baseZeroTwo, baseZeroOne, baseZeroZero
+      , baseZero, baseOne, baseTwo, baseThree, yellow, orange
+      , red, magenta, violet, blue, cyan, green;
+baseZeroThree  :=(0.0               ,0.168627450980392,0.211764705882353);
+baseZeroTwo    :=(0.0274509803921569,0.211764705882353,0.258823529411765);
+baseZeroOne    :=(0.345098039215686 ,0.431372549019608,0.458823529411765);
+baseZeroZero   :=(0.396078431372549 ,0.482352941176471,0.513725490196078);
+baseZero       :=(0.513725490196078 ,0.580392156862745,0.588235294117647);
+baseOne        :=(0.576470588235294 ,0.631372549019608,0.631372549019608);
+baseTwo        :=(0.933333333333333 ,0.909803921568627,0.835294117647059);
+baseThree      :=(0.992156862745098 ,0.964705882352941,0.890196078431372);
+yellow         :=(0.709803921568627 ,0.537254901960784,0.0);
+orange         :=(0.796078431372549 ,0.294117647058824,0.0862745098039216);
+red          :=(0.862745098039216 ,0.196078431372549,0.184313725490196);
+magenta        :=(0.827450980392157 ,0.211764705882353,0.509803921568627);
+violet         :=(0.423529411764706 ,0.443137254901961,0.768627450980392);
+blue         :=(0.149019607843137 ,0.545098039215686,0.823529411764706);
+cyan           :=(0.164705882352941 ,0.631372549019608,0.596078431372549);
+green        :=(0.52156862745098  ,0.6              ,0.0);
+
+
+%%%%%%%%%%%%%%%%%%%%
+% Automata drawing %
+%%%%%%%%%%%%%%%%%%%%
+u:=.5cm; % unity
+gu:=5u;  % distance between states
+nodesize := u; %size of a node
+nodespace := u+.1cm; %size of a node
+
+def resize(expr nu)=
+    u:=nu;
+    gu:=5u;  % distance between states
+    nodesize := u; %size of a node
+    nodespace := u+.1cm; %size of a node
+enddef;
+
+% return the middle of a path
+vardef midpoint(expr p)=
+    save r; pair r;
+    r:=point 1/2length(p) of p;
+    r
+enddef;
+
+% shorten a path of length d at the beginning and the end
+vardef shorten(expr p,d) =
+    save q,bcirc,ecirc;
+    path q,bcirc,ecirc;
+    bcirc := fullcircle scaled d shifted point 0 of p;
+    ecirc := fullcircle scaled d shifted point length(p) of p;
+    q := p cutbefore bcirc cutafter ecirc;
+    q
+enddef;
+
+% Return a rounded box around top left and bottom right point.
+vardef block(expr tl,br) =
+    save p;
+    save d,shift;
+    save topleft,bottomright;
+    save tll,tlt,trt,trr,brr,brb,blb,bll;
+    path p;
+    numeric d,shift;
+    d := 1/3u;
+    shift := 1.2u;
+    pair topleft,bottomright;
+    topleft := tl shifted (-shift,2shift);
+    bottomright := br shifted (shift,-.5shift);
+    pair tll,tlt,trt,trr,brr,brb,blb,bll;
+    tll := topleft shifted (-d,0);
+    tlt := topleft shifted (0,d);
+    trt := (xpart bottomright, ypart topleft) shifted (0,d);
+    trr := (xpart bottomright, ypart topleft) shifted (d,0);
+    brr := bottomright shifted (d,0);
+    brb := bottomright shifted (0,-d);
+    blb := (xpart topleft, ypart bottomright) shifted (0,-d);
+    bll := (xpart topleft, ypart bottomright) shifted (-d,0);
+    p:=tlt---trt..trr---brr..brb---blb..bll---tll..cycle;
+    p
+enddef;
+
+% b being the path of the block
+vardef blockLabelPosition(expr b)=
+    save pos;
+    pair pos;
+    pos := point 0.5 of b;
+    pos
+enddef;
+
+% draw a block with the right math-mode tex label on top of it
+def drawblock(expr topleftpoint, bottomrightpoint, l)=
+    save b,pos;
+    path b;
+    b:=block(topleftpoint,bottomrightpoint);
+    pair pos;
+    pos := blockLabelPosition(b);
+    draw b withcolor base01;
+    label.top(TEX("$"&l&"$"),pos);
+enddef;
+
+% -- Generic private functions
+
+% return the edge between points A and B.
+% out angle from A is inan
+% in angle to B is outan
+% nodesize is the size of the node
+vardef edgeFull(expr posA,posB,inan,outan) =
+    save sub,s;
+    path sub,s;
+    s := posA {dir inan} .. {dir outan} posB ;
+    sub := shorten(s,nodespace);
+    sub
+enddef;
+
+% return a picture of the label l for edge e
+vardef edgeLabel(expr e,l) =
+    save ret,mid,an,lab,height,width;
+    picture ret;
+    pair mid;
+    mid := midpoint(e);
+    numeric an;
+    an := angle (direction 1/2length(e) of e);
+    picture lab;
+    pair height,width;
+    lab:=thelabel(TEX("$"&l&"$"),origin);
+    height:=(0,ypart (ulcorner lab - llcorner lab));
+    width:=(xpart (urcorner lab - ulcorner lab),0);
+    if (an>-35) and (an<35):
+        ret:=lab shifted height rotated an shifted mid;
+    elseif (an>145) or (an<-145):
+        ret:=lab shifted height rotated (an+180) shifted mid;
+    elseif (an>75) and (an<120):
+        ret:=lab shifted mid shifted -width;
+    elseif (an>-120) and (an<-75):
+        ret:=lab shifted mid shifted width;
+    else:
+        ret:=lab shifted mid shifted height;
+    fi;
+    ret
+enddef;
+
+
+
+% --- LABELED GRAPHS ---
+% return the edge between points A and B.
+% out angle from A is an + angle from A to B
+vardef edgeAngle(expr posA,posB,an) =
+    save res,d;
+    path res;
+    numeric d;
+    d := angle(posB-posA);
+    res := edgeFull(posA,posB,d+an,d-an);
+    res
+enddef;
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%                              %%
+%%           LOOPS              %%
+%%                              %%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+vardef dist(expr a,b)=
+    save width,height,res;
+    numeric width,height,res;
+    width:=xpart b - xpart a;
+    height:=ypart b - ypart a;
+    res:=sqrt(width*width + height*height);
+enddef;
+% return a loop
+vardef loopFull(expr a,b,an) =
+    save ba,ea;
+    save circ,p,s;
+    pair ba,ea;
+    path circ,p,s;
+    p:=a{1,1}..b..{1,-1}cycle;
+    circ:= fullcircle scaled nodespace shifted a;
+    ba = circ intersectionpoint (subpath (0,1) of p);
+    ea = circ intersectionpoint (subpath (1,2) of p);
+    s:= ba{1,1}..b..{1,-1}ea;
+    s shifted -a rotated an shifted a
+enddef;
+
+vardef loopPoint(expr a,b) =
+    loopFull(a,b,0)
+enddef;
+
+vardef loopAngle(expr a,an) =
+    loopFull(a,a shifted (0,nodesize),an)
+enddef;
+
+vardef loop(expr a) =
+    loopFull(a,a shifted (0,nodesize),0)
+enddef;
+
+% return the direct edge between A and B
+vardef edge(expr posA,posB) =
+    save an;
+    save sub;
+    numeric an;
+    path sub;
+    if (posA = posB):
+        sub := loop(posA);
+    else:
+        an := angle(posB-posA);
+        sub := edgeFull(posA,posB,an,an);
+    fi
+    sub
+enddef;
+
+def drawLoopPoint(expr a,b,l) =
+    begingroup;
+    save s;
+    path s;
+    s:=loopPoint(a,b);
+    drawarrow s;
+    label.top(TEX("$"&l&"$"),midpoint(s));
+    endgroup;
+enddef;
+def drawLoop(expr a,l) =
+    begingroup;
+    save s;
+    path s;
+    s:=loop(a);
+    drawarrow s;
+    label.top(TEX("$"&l&"$"),midpoint(s));
+    endgroup;
+enddef;
+
+def drawstate(expr pos) =
+    draw pos withpen pencircle scaled 4bp;
+enddef;
+
+% draw some state with some label insize
+def drawState(expr pos,l) =
+    begingroup;
+    save lab,reslab;
+    save height,width;
+    save size;
+    % Draw the circle
+    draw fullcircle scaled nodesize shifted pos;
+
+    % Draw the label with the right size
+    picture lab,reslab;
+    numeric height,width;
+    numeric size;
+    lab=thelabel(TEX("$"&l&"$"),origin);
+    height:=ypart (ulcorner lab - llcorner lab);
+    width :=xpart (urcorner lab - ulcorner lab);
+    size := sqrt(height*height + width*width);
+    if size>.9nodesize:
+        reslab:=lab scaled (.9nodesize/size) shifted pos;
+    else:
+        reslab:=lab shifted pos;
+    fi
+    % help for debug to draw boundaries
+    % draw ulcorner reslab -- urcorner reslab -- lrcorner reslab -- llcorner reslab -- cycle;
+    draw reslab;
+    endgroup;
+enddef;
+
+% draw an edge
+def drawEdgeFull(expr posA,posB,l,inan,outan) =
+    begingroup;
+    save sub;
+    path sub;
+    sub := edgeFull(posA,posB,inan,outan);
+    drawarrow sub;
+    draw edgeLabel(sub,l);
+    endgroup;
+enddef;
+
+def drawEdgeAngle(expr posA,posB,l,inan) =
+    begingroup;
+    save sub;
+    path sub;
+    sub := edgeAngle(posA,posB,inan);
+    drawarrow sub;
+    draw edgeLabel(sub,l);
+    endgroup;
+enddef;
+
+def drawEdge(expr posA,posB,l) =
+    begingroup;
+    save sub;
+    path sub;
+    sub := edge(posA,posB);
+    drawarrow sub;
+    draw edgeLabel(sub,l);
+    endgroup;
+enddef;
+
+vardef box(expr posA) =
+    save b,size;
+    path b;
+    numeric size;
+    size:=2nodesize;
+    b := unitsquare scaled size shifted posA shifted (-.5size,-.5size);
+    b
+enddef;
+
+def drawbox(expr posA,l) =
+    begingroup;
+    save b,pos;
+    path b;
+    pair pos;
+    b:=box(posA);
+    draw b;
+    pos=point 3 of b;
+    label.lrt(TEX("$"&l&"$"),pos);
+    endgroup;
+enddef;
+
+prologues:=3;
+
+verbatimtex
+%&latex
+\documentclass{minimal}
+\begin{document}
+etex
+
+% TEX macro is short enough to be copied
+string preverbatimtex_, postverbatimtex_;
+
+vardef TEXPRE text s =  preverbatimtex_ := s; enddef;
+
+vardef TEXPOST text s =  postverbatimtex_ := s; enddef;
+
+vardef TEX primary s =
+  if known preverbatimtex_:
+    write "verbatimtex "&preverbatimtex_&" etex" to "mptextmp.mp";
+  fi
+  write "btex "&s&" etex" to "mptextmp.mp";
+  if known postverbatimtex_:
+    write "verbatimtex "&postverbatimtex_&" etex" to "mptextmp.mp";
+  fi
+  write EOF to "mptextmp.mp";
+  scantokens "input mptextmp"
+enddef;
+
+TEXPRE("\documentclass{minimal}\begin{document}");
+TEXPOST("\end{document}");