diff --git a/man/MeshObject.Rd b/man/MeshObject.Rd
index 4940034..e9c373a 100644
--- a/man/MeshObject.Rd
+++ b/man/MeshObject.Rd
@@ -3,11 +3,14 @@
 \name{Mesh}
 \alias{Mesh}
 \alias{Mesh,list-method}
+\alias{Mesh,triangulation-method}
 \title{Create mesh object}
 \usage{
 Mesh(domain)
 
 \S4method{Mesh}{list}(domain)
+
+\S4method{Mesh}{triangulation}(domain)
 }
 \arguments{
 \item{domain}{A named list containing must contain:
diff --git a/man/MeshObject_times_vector.Rd b/man/MeshObject_times_vector.Rd
index 86a24d1..23d1a77 100644
--- a/man/MeshObject_times_vector.Rd
+++ b/man/MeshObject_times_vector.Rd
@@ -3,7 +3,7 @@
 \name{\%X\%}
 \alias{\%X\%}
 \alias{\%X\%,MeshObject,numeric-method}
-\title{Spatio-temporal domain}
+\title{create spatio-temporal domain}
 \usage{
 op1 \%X\% op2
 
@@ -18,5 +18,5 @@ op1 \%X\% op2
 An S4 object representing a spatio-temporal domain.
 }
 \description{
-Spatio-temporal domain
+create spatio-temporal domain
 }
diff --git a/man/div.Rd b/man/div.Rd
index 0823406..0023da4 100644
--- a/man/div.Rd
+++ b/man/div.Rd
@@ -2,7 +2,7 @@
 % Please edit documentation in R/operators.R
 \name{div}
 \alias{div}
-\title{divergence operator}
+\title{divergence operator FunctionGradObject}
 \usage{
 div(f)
 }
@@ -13,7 +13,7 @@ div(f)
 A S4 object representing the diffusion term of a second order linear differential operator.
 }
 \description{
-divergence operator
+divergence operator FunctionGradObject
 }
 \examples{
 \dontrun{
diff --git a/man/dot_product.Rd b/man/dot_product.Rd
new file mode 100644
index 0000000..79b7a54
--- /dev/null
+++ b/man/dot_product.Rd
@@ -0,0 +1,33 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/operators.R
+\name{dot}
+\alias{dot}
+\alias{dot,vector,FunctionGradObject-method}
+\title{dot product between vector and FunctionGradObject}
+\usage{
+dot(op1, op2)
+
+\S4method{dot}{vector,FunctionGradObject}(op1, op2)
+}
+\arguments{
+\item{op1}{a numeric vector.}
+
+\item{op2}{a FunctionGradObject.}
+}
+\value{
+A S4 object representing the advection term of a second order linear differential operator.
+}
+\description{
+dot product between vector and FunctionGradObject
+}
+\examples{
+\dontrun{
+library(femR)
+data("unit_square")
+mesh <- Mesh(unit_square)
+Vh <- FunctionSpace(mesh)
+f <- Function(Vh)
+b <- c(1,1)
+advection <- dot(b,grad(f))
+} 
+}
diff --git a/man/dt-FunctionObject-missing-missing-method.Rd b/man/dt-FunctionObject-missing-missing-method.Rd
index a228112..218b09a 100644
--- a/man/dt-FunctionObject-missing-missing-method.Rd
+++ b/man/dt-FunctionObject-missing-missing-method.Rd
@@ -2,18 +2,22 @@
 % Please edit documentation in R/operators.R
 \name{dt,FunctionObject,missing,missing-method}
 \alias{dt,FunctionObject,missing,missing-method}
-\title{dt function overload for FunctionObejct}
+\title{time derivate of FunctionObejct}
 \usage{
 \S4method{dt}{FunctionObject,missing,missing}(x, df, ncp)
 }
 \arguments{
-\item{x}{a FunctionObject:}
+\item{x}{a FunctionObject.}
+
+\item{df}{missing.}
+
+\item{ncp}{missing.}
 }
 \value{
 A S4 object representing the time derivative of a FunctionObject.
 }
 \description{
-dt function overload for FunctionObejct
+time derivate of FunctionObejct
 }
 \examples{
 \dontrun{
diff --git a/man/grad.Rd b/man/grad.Rd
index 6f0fa9b..39de6fc 100644
--- a/man/grad.Rd
+++ b/man/grad.Rd
@@ -3,7 +3,7 @@
 \name{grad}
 \alias{grad}
 \alias{grad,FunctionObject-method}
-\title{Take gradient of FunctionObject}
+\title{compute gradient of FunctionObject}
 \usage{
 grad(f)
 
@@ -16,7 +16,7 @@ grad(f)
 An S4 object representing the gradient of the FunctionObject passed as parameter.
 }
 \description{
-Take gradient of FunctionObject
+compute gradient of FunctionObject
 }
 \examples{
 \dontrun{
diff --git a/man/laplace.Rd b/man/laplace.Rd
index a5da1f2..532a04d 100644
--- a/man/laplace.Rd
+++ b/man/laplace.Rd
@@ -2,7 +2,7 @@
 % Please edit documentation in R/operators.R
 \name{laplace}
 \alias{laplace}
-\title{laplace operator}
+\title{laplace operator for FunctionObject}
 \usage{
 laplace(f)
 }
@@ -13,7 +13,7 @@ laplace(f)
 A S4 object representing the laplace operator applied to the function passed as parameter.
 }
 \description{
-laplace operator
+laplace operator for FunctionObject
 }
 \examples{
 \dontrun{
diff --git a/man/minus_DiffOb_op.Rd b/man/minus_DiffOb_op.Rd
new file mode 100644
index 0000000..18bdb56
--- /dev/null
+++ b/man/minus_DiffOb_op.Rd
@@ -0,0 +1,22 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/operators.R
+\name{-,DiffOpObject,DiffOpObject-method}
+\alias{-,DiffOpObject,DiffOpObject-method}
+\alias{-,DiffOpObject,missing-method}
+\title{difference of differential operators}
+\usage{
+\S4method{-}{DiffOpObject,DiffOpObject}(e1, e2)
+
+\S4method{-}{DiffOpObject,missing}(e1)
+}
+\arguments{
+\item{e1}{a DiffOpObject.}
+
+\item{e2}{a DiffOpObject.}
+}
+\value{
+A S4 object representing the difference of two differential operators.
+}
+\description{
+difference of differential operators
+}
diff --git a/man/pde.Rd b/man/pde.Rd
index 2523cec..e58d4f3 100644
--- a/man/pde.Rd
+++ b/man/pde.Rd
@@ -22,7 +22,7 @@ Pde(L, u, dirichletBC, initialCondition)
 
 \item{dirichletBC}{the Dirichlet boundary conditions to be imposed on the boundary of the domain. If not provided, homogeneous Dirichlet boundary conditions will be imposed.}
 
-\item{initilaCondition}{the initial condition of a parabolic problem.}
+\item{initialCondition}{the initial condition of a parabolic problem.}
 }
 \value{
 A S4 object representing a PDE.
diff --git a/man/times-numeric-FunctionObject-method.Rd b/man/times-numeric-FunctionObject-method.Rd
index 2b07c7b..6de53fc 100644
--- a/man/times-numeric-FunctionObject-method.Rd
+++ b/man/times-numeric-FunctionObject-method.Rd
@@ -2,12 +2,12 @@
 % Please edit documentation in R/operators.R
 \name{*,numeric,FunctionObject-method}
 \alias{*,numeric,FunctionObject-method}
-\title{product overload for FunctionObejct}
+\title{product by scalar for FunctionObejct}
 \usage{
 \S4method{*}{numeric,FunctionObject}(e1, e2)
 }
 \arguments{
-\item{e1}{a numeric:}
+\item{e1}{a numeric.}
 
 \item{e2}{a FunctioObject created by \code{Function}.}
 }
@@ -15,7 +15,7 @@
 A S4 object representing the reaction term of a second order linear differential operator.
 }
 \description{
-product overload for FunctionObejct
+product by scalar for FunctionObejct
 }
 \examples{
 \dontrun{
diff --git a/man/unit_square.Rd b/man/unit_square.Rd
new file mode 100644
index 0000000..5909264
--- /dev/null
+++ b/man/unit_square.Rd
@@ -0,0 +1,10 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/datasets.R
+\name{unit_square}
+\alias{unit_square}
+\title{Unit square domain}
+\description{
+The boundary and interior nodes and connectivity matrix of a triangular mesh of
+the unit square domain. 
+This dataset can be used to create a mesh object with the function \code{Mesh}.
+}