anchor.diff:  ! DATA DICTIONARY
   real::mesh_size, x_dim=1.0, y_dim=1.0
   integer::n, m
  -real,allocatable::a_n(:,:), a_s(:,:), a_e(:,:), a_w(:,:), phi(:,:), gamma(:,:)
  +real,allocatable::a_p(:,:), a_n(:,:), a_s(:,:), a_e(:,:), a_w(:,:), phi(:,:), gamma(:,:)
   integer::i,j,k
  -real::a_p,delta,relaxation=0.8
  +real::delta,relaxation=0.8
   
   ! GET THE MESH SIZE
   write(*,*)'Enter the mesh size:'
  
positive.code: end do
  
  ! DEALLOCATE THE ARRAYS
  deallocate(a_n)
  deallocate(a_s)
  deallocate(a_e)
  
negative.code: m = int(y_dim/mesh_size)-1
  
  ! ALLOCATE THE ARRAYS
  allocate(a_p(1:n,1:m))
  allocate(a_n(1:n,1:m))
  allocate(a_s(1:n,1:m))
  allocate(a_e(1:n,1:m))
  allocate(a_w(1:n,1:m))
  allocate(gamma(1:n,1:m))
  
  allocate(phi(0:n+1,0:m+1))
  
  ! INITIALIZE THE ARRAY VALUES
  gamma = 1.0
  