Some improvements to the wording on the sign convention section.

notation.rst

@@ -343,36 +343,36 @@ In the first row (a, b, c) of :numref:`fig-notation-rotation-sign-convention`
 there are three ways to indicate leader arrows on the angular dimension
 :math:`q` for a positive right handed orientation of :math:`A` with respect to
 :math:`N`. A positive value of :math:`q` gives a positive right handed
-orientation. This corresponds to the SymPy Mechanics command ``A.orient_axis(N,
-q, N.z)``. In the second row (d, e, f), three ways are shown to indicate leader
-arrows on the angular dimension :math:`q` for a negative right handed
-orientation of :math:`A` with respect to :math:`N`. A positive value of
-:math:`q` causes a negative right handed orientation. This row corresponds to
-the SymPy Mechanics commands ``A.orient_axis(N, -q, N.z)`` or
+orientation in a), b), and c). This corresponds to the SymPy Mechanics command
+``A.orient_axis(N, q, N.z)``. In the second row (d, e, f), three ways are shown
+to indicate leader arrows on the angular dimension :math:`q` for a negative
+right handed orientation of :math:`A` with respect to :math:`N`. A positive
+value of :math:`q` causes a negative right handed orientation. This row
+corresponds to the SymPy Mechanics commands ``A.orient_axis(N, -q, N.z)`` or
 ``A.orient_axis(N, q, -N.z)``. In g) a negative sign is indicated on :math:`q`.
 It is sometimes convenient to draw the rotation in negative right handed
-rotation and by labeling the value :math:`-q` g) is equivalent to a). We try to
-do this sparingly.
+rotation and by labeling the value :math:`-q`. This means that g) is equivalent
+to a). We try to do this sparingly.
 
 .. _fig-notation-rotation-dimension-sign-convention:
 .. figure:: figures/notation-rotation-dimension-sign-convention.svg
 
    Options for adding arrows to angular dimensions for positive (first row) and
    negative (second row) orientations.
 
-In figure :numref:`fig-notation-vector-sign-convention` various vectors are shown.
-Vectors are always drawn with a single arrow to indicate the positive sense of
-the vector. In a) the vector acting on body :math:`A` is :math:`-F\hat{n}_x`
-and the vector actin gon body :math:`B` is :math:`F\hax{n}_x`. The variable
-:math:`F` indicated beside the arrow means that a positive value of :math:`F`
-has the corresponding sense as the vector arrow head. The sense changes for
-both vectors in b) and for one in c). In d), a negative :math:`F` is indicated.
-This makes d) equivalent to a). The negative sense for that vector is shown
-when :math:`-F` is beside it.
+In figure :numref:`fig-notation-vector-sign-convention` various vectors are
+shown.  Vectors are always drawn with a single arrow to indicate the positive
+sense of the vector. In a) the vector acting on body :math:`A` is
+:math:`-F\hat{n}_x` and the vector acting on body :math:`B` is
+:math:`F\hax{n}_x`. The variable :math:`F` indicated beside the arrow means
+that a positive value of :math:`F` has the corresponding sense as the vector
+arrow head. The sense changes for both vectors in b) and for one vector in c).
+In d), a negative :math:`F` is indicated.  This makes d) equivalent to a). The
+negative sense for that vector is shown when :math:`-F` is beside it.
 
 .. _fig-notation-vector-sign-convention:
 .. figure:: figures/notation-vector-sign-convention.svg
 
    Various ways to draw vector arrows, where the arrow head indicates the
-   positive sense of the vector if the variable is positive and negative sense
-   if the variable is shown as negative.
+   positive sense of the vector if the variable has no sign and negative sense
+   if the variable has a negative sign.