// Laplace equation
border aaa(t=0,1){x=t;y=0;};
border bbb(t=0,0.5){x=1;y=t;};
border ccc(t=0,0.5){x=1-t;y=0.5;};
border ddd(t=0.5,1){x=0.5;y=t;};
border eee(t=0.5,1){x=1-t;y=1;};
border fff(t=0,1){x=0;y=1-t;};
mesh Th = buildmesh (aaa(6) + bbb(4) + ccc(4) +ddd(4) + eee(4) + fff(6));
fespace Vh(Th,P1);  //change P1 in P2 to make P2 finite element.
Vh u=0,v;
func f= 1;
func g= 0;
int i=0;
real error=0.1;
real coef= 0.1^(1./5.);
  
problem Problem1(u,v,solver=CG,eps=1.0e-6)
  =int2d(Th)(  dx(u)*dx(v) + dy(u)*dy(v)) 
  + int2d(Th) ( v*f ) 
  + on(aaa,bbb,ccc,ddd,eee,fff,u=g)  ;
  
plot(u,Th,wait=1);

for (i=0;i< 6;i++)
{   
  real d = clock();
  Problem1; //  solve the problem 
  plot(u,wait=1);
  cout << "Adaptation de maillage" << endl;
  Th=adaptmesh(Th,u,inquire=1,err=error);
  error = error * coef;
};
plot(u);
cout<< "program finished normaly" <<endl;