Update poisson_dev_fe.jl

Author: amartinhuertas

src/poisson_dev_fe.jl

@@ -571,7 +571,7 @@ low_level_manual_gradient_dv_array = lazy_map(Broadcasting(Operation(⋅)),inv_J
 
 # ## A low-level implementation of the residual integration and assembly
 
-# In the rest of the tutorial we aim to solve a Poisson equation with homogeneous source term, i.e., $f=0$ and non-homogeneous Dirichlet boundary conditions $u=g_0$ on $\Gamma_D$, with  $\Gamma_D$ being the whole boundary of the model. While the strong imposition of non-homogeneous Dirichlet boundary conditions in Gridap is done under the hood by modifying the global assembly process by subtracting the contributions of boundary conditions to the right hand side of the linear system, in this tutorial, for simplicity, we follow a different approach. This approach requires: (1) to be able to assemble the residual of the PDE for an arbitrary finite element function $\hat{u}_h$ (current section); (2) to be able to assemble the coefficient matrix of the finite element linear system (next section). We briefly outline this solution approach in the sequel.
+# In the rest of the tutorial we aim to solve a Poisson equation with homogeneous source term, i.e., $f=0$ and non-homogeneous Dirichlet boundary conditions $u=g_0$ on $\Gamma_D$, with  $\Gamma_D$ being the whole boundary of the model. While the strong imposition of non-homogeneous Dirichlet boundary conditions in Gridap is done under the hood by modifying the global assembly process by subtracting the contributions of boundary conditions from the right hand side of the linear system, in this tutorial, for simplicity, we follow a different approach. This approach requires: (1) to be able to assemble the residual of the PDE for an arbitrary finite element function $\hat{u}_h$ (current section); (2) to be able to assemble the coefficient matrix of the finite element linear system (next section). We briefly outline this solution approach in the sequel.
 
 # The discretized variational form of the Poisson problem reads as:
 # >Find $u_h \in V_h^{\Gamma_D}=\{v_h \in V_h:v_h=g^h_0 \; on \; \Gamma_D\}$ such that