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Degree 2 Brezzi–Douglas–Marini on a tetrahedron

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In this example:
\(\displaystyle l_{0}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{0}}\boldsymbol{v}\cdot(2 s_{0}^{2} + 4 s_{0} s_{1} - 3 s_{0} + 2 s_{1}^{2} - 3 s_{1} + 1)\hat{\boldsymbol{n}}_{0}\)
where \(f_{0}\) is the 0th face;
\(\hat{\boldsymbol{n}}_{0}\) is the normal to facet 0;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{0}\).

\(\displaystyle \boldsymbol{\phi}_{0} = \left(\begin{array}{c}\displaystyle 24 x \left(5 x - 2\right)\\\displaystyle 12 y \left(1 - 5 x\right)\\\displaystyle 12 z \left(1 - 5 x\right)\end{array}\right)\)

This DOF is associated with face 0 of the reference element.
\(\displaystyle l_{1}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{0}}\boldsymbol{v}\cdot(s_{0} \cdot \left(2 s_{0} - 1\right))\hat{\boldsymbol{n}}_{0}\)
where \(f_{0}\) is the 0th face;
\(\hat{\boldsymbol{n}}_{0}\) is the normal to facet 0;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{0}\).

\(\displaystyle \boldsymbol{\phi}_{1} = \left(\begin{array}{c}\displaystyle 12 x \left(1 - 5 y\right)\\\displaystyle 24 y \left(5 y - 2\right)\\\displaystyle 12 z \left(1 - 5 y\right)\end{array}\right)\)

This DOF is associated with face 0 of the reference element.
\(\displaystyle l_{2}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{0}}\boldsymbol{v}\cdot(s_{1} \cdot \left(2 s_{1} - 1\right))\hat{\boldsymbol{n}}_{0}\)
where \(f_{0}\) is the 0th face;
\(\hat{\boldsymbol{n}}_{0}\) is the normal to facet 0;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{0}\).

\(\displaystyle \boldsymbol{\phi}_{2} = \left(\begin{array}{c}\displaystyle 12 x \left(1 - 5 z\right)\\\displaystyle 12 y \left(1 - 5 z\right)\\\displaystyle 24 z \left(5 z - 2\right)\end{array}\right)\)

This DOF is associated with face 0 of the reference element.
\(\displaystyle l_{3}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{0}}\boldsymbol{v}\cdot(4 s_{0} s_{1})\hat{\boldsymbol{n}}_{0}\)
where \(f_{0}\) is the 0th face;
\(\hat{\boldsymbol{n}}_{0}\) is the normal to facet 0;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{0}\).

\(\displaystyle \boldsymbol{\phi}_{3} = \left(\begin{array}{c}\displaystyle 6 x \left(- 5 y - 5 z + 2\right)\\\displaystyle 3 y \left(5 y + 20 z - 6\right)\\\displaystyle 3 z \left(20 y + 5 z - 6\right)\end{array}\right)\)

This DOF is associated with face 0 of the reference element.
\(\displaystyle l_{4}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{0}}\boldsymbol{v}\cdot(4 s_{1} \left(- s_{0} - s_{1} + 1\right))\hat{\boldsymbol{n}}_{0}\)
where \(f_{0}\) is the 0th face;
\(\hat{\boldsymbol{n}}_{0}\) is the normal to facet 0;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{0}\).

\(\displaystyle \boldsymbol{\phi}_{4} = \left(\begin{array}{c}\displaystyle 3 x \left(5 x + 20 z - 6\right)\\\displaystyle 6 y \left(- 5 x - 5 z + 2\right)\\\displaystyle 3 z \left(20 x + 5 z - 6\right)\end{array}\right)\)

This DOF is associated with face 0 of the reference element.
\(\displaystyle l_{5}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{0}}\boldsymbol{v}\cdot(4 s_{0} \left(- s_{0} - s_{1} + 1\right))\hat{\boldsymbol{n}}_{0}\)
where \(f_{0}\) is the 0th face;
\(\hat{\boldsymbol{n}}_{0}\) is the normal to facet 0;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{0}\).

\(\displaystyle \boldsymbol{\phi}_{5} = \left(\begin{array}{c}\displaystyle 3 x \left(5 x + 20 y - 6\right)\\\displaystyle 3 y \left(20 x + 5 y - 6\right)\\\displaystyle 6 z \left(- 5 x - 5 y + 2\right)\end{array}\right)\)

This DOF is associated with face 0 of the reference element.
\(\displaystyle l_{6}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{1}}\boldsymbol{v}\cdot(2 s_{0}^{2} + 4 s_{0} s_{1} - 3 s_{0} + 2 s_{1}^{2} - 3 s_{1} + 1)\hat{\boldsymbol{n}}_{1}\)
where \(f_{1}\) is the 1st face;
\(\hat{\boldsymbol{n}}_{1}\) is the normal to facet 1;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{1}\).

\(\displaystyle \boldsymbol{\phi}_{6} = \left(\begin{array}{c}\displaystyle 120 x^{2} + 300 x y + 300 x z - 192 x + 180 y^{2} + 360 y z - 240 y + 180 z^{2} - 240 z + 72\\\displaystyle 12 y \left(- 5 x - 5 y - 5 z + 4\right)\\\displaystyle 12 z \left(- 5 x - 5 y - 5 z + 4\right)\end{array}\right)\)

This DOF is associated with face 1 of the reference element.
\(\displaystyle l_{7}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{1}}\boldsymbol{v}\cdot(s_{0} \cdot \left(2 s_{0} - 1\right))\hat{\boldsymbol{n}}_{1}\)
where \(f_{1}\) is the 1st face;
\(\hat{\boldsymbol{n}}_{1}\) is the normal to facet 1;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{1}\).

\(\displaystyle \boldsymbol{\phi}_{7} = \left(\begin{array}{c}\displaystyle 60 x y - 12 x + 180 y^{2} - 120 y + 12\\\displaystyle 24 y \left(2 - 5 y\right)\\\displaystyle 12 z \left(5 y - 1\right)\end{array}\right)\)

This DOF is associated with face 1 of the reference element.
\(\displaystyle l_{8}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{1}}\boldsymbol{v}\cdot(s_{1} \cdot \left(2 s_{1} - 1\right))\hat{\boldsymbol{n}}_{1}\)
where \(f_{1}\) is the 1st face;
\(\hat{\boldsymbol{n}}_{1}\) is the normal to facet 1;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{1}\).

\(\displaystyle \boldsymbol{\phi}_{8} = \left(\begin{array}{c}\displaystyle 60 x z - 12 x + 180 z^{2} - 120 z + 12\\\displaystyle 12 y \left(5 z - 1\right)\\\displaystyle 24 z \left(2 - 5 z\right)\end{array}\right)\)

This DOF is associated with face 1 of the reference element.
\(\displaystyle l_{9}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{1}}\boldsymbol{v}\cdot(4 s_{0} s_{1})\hat{\boldsymbol{n}}_{1}\)
where \(f_{1}\) is the 1st face;
\(\hat{\boldsymbol{n}}_{1}\) is the normal to facet 1;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{1}\).

\(\displaystyle \boldsymbol{\phi}_{9} = \left(\begin{array}{c}\displaystyle 30 x y + 30 x z - 12 x + 45 y^{2} + 180 y z - 60 y + 45 z^{2} - 60 z + 12\\\displaystyle 3 y \left(- 5 y - 20 z + 6\right)\\\displaystyle 3 z \left(- 20 y - 5 z + 6\right)\end{array}\right)\)

This DOF is associated with face 1 of the reference element.
\(\displaystyle l_{10}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{1}}\boldsymbol{v}\cdot(4 s_{1} \left(- s_{0} - s_{1} + 1\right))\hat{\boldsymbol{n}}_{1}\)
where \(f_{1}\) is the 1st face;
\(\hat{\boldsymbol{n}}_{1}\) is the normal to facet 1;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{1}\).

\(\displaystyle \boldsymbol{\phi}_{10} = \left(\begin{array}{c}\displaystyle 15 x^{2} + 60 x y - 90 x z - 12 x + 45 y^{2} - 90 y z - 30 y - 90 z^{2} + 90 z - 3\\\displaystyle 6 y \left(- 5 x - 5 y + 3\right)\\\displaystyle 3 z \left(20 x + 20 y + 15 z - 14\right)\end{array}\right)\)

This DOF is associated with face 1 of the reference element.
\(\displaystyle l_{11}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{1}}\boldsymbol{v}\cdot(4 s_{0} \left(- s_{0} - s_{1} + 1\right))\hat{\boldsymbol{n}}_{1}\)
where \(f_{1}\) is the 1st face;
\(\hat{\boldsymbol{n}}_{1}\) is the normal to facet 1;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{1}\).

\(\displaystyle \boldsymbol{\phi}_{11} = \left(\begin{array}{c}\displaystyle 15 x^{2} - 90 x y + 60 x z - 12 x - 90 y^{2} - 90 y z + 90 y + 45 z^{2} - 30 z - 3\\\displaystyle 3 y \left(20 x + 15 y + 20 z - 14\right)\\\displaystyle 6 z \left(- 5 x - 5 z + 3\right)\end{array}\right)\)

This DOF is associated with face 1 of the reference element.
\(\displaystyle l_{12}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{2}}\boldsymbol{v}\cdot(2 s_{0}^{2} + 4 s_{0} s_{1} - 3 s_{0} + 2 s_{1}^{2} - 3 s_{1} + 1)\hat{\boldsymbol{n}}_{2}\)
where \(f_{2}\) is the 2nd face;
\(\hat{\boldsymbol{n}}_{2}\) is the normal to facet 2;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{2}\).

\(\displaystyle \boldsymbol{\phi}_{12} = \left(\begin{array}{c}\displaystyle 12 x \left(5 x + 5 y + 5 z - 4\right)\\\displaystyle - 180 x^{2} - 300 x y - 360 x z + 240 x - 120 y^{2} - 300 y z + 192 y - 180 z^{2} + 240 z - 72\\\displaystyle 12 z \left(5 x + 5 y + 5 z - 4\right)\end{array}\right)\)

This DOF is associated with face 2 of the reference element.
\(\displaystyle l_{13}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{2}}\boldsymbol{v}\cdot(s_{0} \cdot \left(2 s_{0} - 1\right))\hat{\boldsymbol{n}}_{2}\)
where \(f_{2}\) is the 2nd face;
\(\hat{\boldsymbol{n}}_{2}\) is the normal to facet 2;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{2}\).

\(\displaystyle \boldsymbol{\phi}_{13} = \left(\begin{array}{c}\displaystyle 24 x \left(5 x - 2\right)\\\displaystyle - 180 x^{2} - 60 x y + 120 x + 12 y - 12\\\displaystyle 12 z \left(1 - 5 x\right)\end{array}\right)\)

This DOF is associated with face 2 of the reference element.
\(\displaystyle l_{14}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{2}}\boldsymbol{v}\cdot(s_{1} \cdot \left(2 s_{1} - 1\right))\hat{\boldsymbol{n}}_{2}\)
where \(f_{2}\) is the 2nd face;
\(\hat{\boldsymbol{n}}_{2}\) is the normal to facet 2;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{2}\).

\(\displaystyle \boldsymbol{\phi}_{14} = \left(\begin{array}{c}\displaystyle 12 x \left(1 - 5 z\right)\\\displaystyle - 60 y z + 12 y - 180 z^{2} + 120 z - 12\\\displaystyle 24 z \left(5 z - 2\right)\end{array}\right)\)

This DOF is associated with face 2 of the reference element.
\(\displaystyle l_{15}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{2}}\boldsymbol{v}\cdot(4 s_{0} s_{1})\hat{\boldsymbol{n}}_{2}\)
where \(f_{2}\) is the 2nd face;
\(\hat{\boldsymbol{n}}_{2}\) is the normal to facet 2;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{2}\).

\(\displaystyle \boldsymbol{\phi}_{15} = \left(\begin{array}{c}\displaystyle 3 x \left(5 x + 20 z - 6\right)\\\displaystyle - 45 x^{2} - 30 x y - 180 x z + 60 x - 30 y z + 12 y - 45 z^{2} + 60 z - 12\\\displaystyle 3 z \left(20 x + 5 z - 6\right)\end{array}\right)\)

This DOF is associated with face 2 of the reference element.
\(\displaystyle l_{16}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{2}}\boldsymbol{v}\cdot(4 s_{1} \left(- s_{0} - s_{1} + 1\right))\hat{\boldsymbol{n}}_{2}\)
where \(f_{2}\) is the 2nd face;
\(\hat{\boldsymbol{n}}_{2}\) is the normal to facet 2;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{2}\).

\(\displaystyle \boldsymbol{\phi}_{16} = \left(\begin{array}{c}\displaystyle 6 x \left(5 x + 5 y - 3\right)\\\displaystyle - 45 x^{2} - 60 x y + 90 x z + 30 x - 15 y^{2} + 90 y z + 12 y + 90 z^{2} - 90 z + 3\\\displaystyle 3 z \left(- 20 x - 20 y - 15 z + 14\right)\end{array}\right)\)

This DOF is associated with face 2 of the reference element.
\(\displaystyle l_{17}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{2}}\boldsymbol{v}\cdot(4 s_{0} \left(- s_{0} - s_{1} + 1\right))\hat{\boldsymbol{n}}_{2}\)
where \(f_{2}\) is the 2nd face;
\(\hat{\boldsymbol{n}}_{2}\) is the normal to facet 2;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{2}\).

\(\displaystyle \boldsymbol{\phi}_{17} = \left(\begin{array}{c}\displaystyle 3 x \left(- 15 x - 20 y - 20 z + 14\right)\\\displaystyle 90 x^{2} + 90 x y + 90 x z - 90 x - 15 y^{2} - 60 y z + 12 y - 45 z^{2} + 30 z + 3\\\displaystyle 6 z \left(5 y + 5 z - 3\right)\end{array}\right)\)

This DOF is associated with face 2 of the reference element.
\(\displaystyle l_{18}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{3}}\boldsymbol{v}\cdot(2 s_{0}^{2} + 4 s_{0} s_{1} - 3 s_{0} + 2 s_{1}^{2} - 3 s_{1} + 1)\hat{\boldsymbol{n}}_{3}\)
where \(f_{3}\) is the 3rd face;
\(\hat{\boldsymbol{n}}_{3}\) is the normal to facet 3;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{3}\).

\(\displaystyle \boldsymbol{\phi}_{18} = \left(\begin{array}{c}\displaystyle 12 x \left(- 5 x - 5 y - 5 z + 4\right)\\\displaystyle 12 y \left(- 5 x - 5 y - 5 z + 4\right)\\\displaystyle 180 x^{2} + 360 x y + 300 x z - 240 x + 180 y^{2} + 300 y z - 240 y + 120 z^{2} - 192 z + 72\end{array}\right)\)

This DOF is associated with face 3 of the reference element.
\(\displaystyle l_{19}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{3}}\boldsymbol{v}\cdot(s_{0} \cdot \left(2 s_{0} - 1\right))\hat{\boldsymbol{n}}_{3}\)
where \(f_{3}\) is the 3rd face;
\(\hat{\boldsymbol{n}}_{3}\) is the normal to facet 3;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{3}\).

\(\displaystyle \boldsymbol{\phi}_{19} = \left(\begin{array}{c}\displaystyle 24 x \left(2 - 5 x\right)\\\displaystyle 12 y \left(5 x - 1\right)\\\displaystyle 180 x^{2} + 60 x z - 120 x - 12 z + 12\end{array}\right)\)

This DOF is associated with face 3 of the reference element.
\(\displaystyle l_{20}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{3}}\boldsymbol{v}\cdot(s_{1} \cdot \left(2 s_{1} - 1\right))\hat{\boldsymbol{n}}_{3}\)
where \(f_{3}\) is the 3rd face;
\(\hat{\boldsymbol{n}}_{3}\) is the normal to facet 3;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{3}\).

\(\displaystyle \boldsymbol{\phi}_{20} = \left(\begin{array}{c}\displaystyle 12 x \left(5 y - 1\right)\\\displaystyle 24 y \left(2 - 5 y\right)\\\displaystyle 180 y^{2} + 60 y z - 120 y - 12 z + 12\end{array}\right)\)

This DOF is associated with face 3 of the reference element.
\(\displaystyle l_{21}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{3}}\boldsymbol{v}\cdot(4 s_{0} s_{1})\hat{\boldsymbol{n}}_{3}\)
where \(f_{3}\) is the 3rd face;
\(\hat{\boldsymbol{n}}_{3}\) is the normal to facet 3;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{3}\).

\(\displaystyle \boldsymbol{\phi}_{21} = \left(\begin{array}{c}\displaystyle 3 x \left(- 5 x - 20 y + 6\right)\\\displaystyle 3 y \left(- 20 x - 5 y + 6\right)\\\displaystyle 45 x^{2} + 180 x y + 30 x z - 60 x + 45 y^{2} + 30 y z - 60 y - 12 z + 12\end{array}\right)\)

This DOF is associated with face 3 of the reference element.
\(\displaystyle l_{22}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{3}}\boldsymbol{v}\cdot(4 s_{1} \left(- s_{0} - s_{1} + 1\right))\hat{\boldsymbol{n}}_{3}\)
where \(f_{3}\) is the 3rd face;
\(\hat{\boldsymbol{n}}_{3}\) is the normal to facet 3;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{3}\).

\(\displaystyle \boldsymbol{\phi}_{22} = \left(\begin{array}{c}\displaystyle 6 x \left(- 5 x - 5 z + 3\right)\\\displaystyle 3 y \left(20 x + 15 y + 20 z - 14\right)\\\displaystyle 45 x^{2} - 90 x y + 60 x z - 30 x - 90 y^{2} - 90 y z + 90 y + 15 z^{2} - 12 z - 3\end{array}\right)\)

This DOF is associated with face 3 of the reference element.
\(\displaystyle l_{23}:\boldsymbol{v}\mapsto\displaystyle\int_{f_{3}}\boldsymbol{v}\cdot(4 s_{0} \left(- s_{0} - s_{1} + 1\right))\hat{\boldsymbol{n}}_{3}\)
where \(f_{3}\) is the 3rd face;
\(\hat{\boldsymbol{n}}_{3}\) is the normal to facet 3;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(f_{3}\).

\(\displaystyle \boldsymbol{\phi}_{23} = \left(\begin{array}{c}\displaystyle 3 x \left(15 x + 20 y + 20 z - 14\right)\\\displaystyle 6 y \left(- 5 y - 5 z + 3\right)\\\displaystyle - 90 x^{2} - 90 x y - 90 x z + 90 x + 45 y^{2} + 60 y z - 30 y + 15 z^{2} - 12 z - 3\end{array}\right)\)

This DOF is associated with face 3 of the reference element.
\(\displaystyle l_{24}:\boldsymbol{v}\mapsto\displaystyle\int_{R}\boldsymbol{v}\cdot\left(\begin{array}{c}0\\- s_{2}\\s_{1}\end{array}\right)\)
where \(R\) is the reference element;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(R\).

\(\displaystyle \boldsymbol{\phi}_{24} = \left(\begin{array}{c}\displaystyle 60 x \left(- y + z\right)\\\displaystyle 60 y \left(- y - 5 z + 1\right)\\\displaystyle 60 z \left(5 y + z - 1\right)\end{array}\right)\)

This DOF is associated with volume 0 of the reference element.
\(\displaystyle l_{25}:\boldsymbol{v}\mapsto\displaystyle\int_{R}\boldsymbol{v}\cdot\left(\begin{array}{c}- s_{2}\\0\\s_{0}\end{array}\right)\)
where \(R\) is the reference element;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(R\).

\(\displaystyle \boldsymbol{\phi}_{25} = \left(\begin{array}{c}\displaystyle 60 x \left(- x - 5 z + 1\right)\\\displaystyle 60 y \left(- x + z\right)\\\displaystyle 60 z \left(5 x + z - 1\right)\end{array}\right)\)

This DOF is associated with volume 0 of the reference element.
\(\displaystyle l_{26}:\boldsymbol{v}\mapsto\displaystyle\int_{R}\boldsymbol{v}\cdot\left(\begin{array}{c}- s_{1}\\s_{0}\\0\end{array}\right)\)
where \(R\) is the reference element;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(R\).

\(\displaystyle \boldsymbol{\phi}_{26} = \left(\begin{array}{c}\displaystyle 60 x \left(- x - 5 y + 1\right)\\\displaystyle 60 y \left(5 x + y - 1\right)\\\displaystyle 60 z \left(- x + y\right)\end{array}\right)\)

This DOF is associated with volume 0 of the reference element.
\(\displaystyle l_{27}:\boldsymbol{v}\mapsto\displaystyle\int_{R}\boldsymbol{v}\cdot\left(\begin{array}{c}s_{2}\\s_{2}\\- s_{0} - s_{1} + 1\end{array}\right)\)
where \(R\) is the reference element;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(R\).

\(\displaystyle \boldsymbol{\phi}_{27} = \left(\begin{array}{c}\displaystyle 60 x \left(x + y + 2 z - 1\right)\\\displaystyle 60 y \left(x + y + 2 z - 1\right)\\\displaystyle 60 z \left(- 5 x - 5 y - 4 z + 4\right)\end{array}\right)\)

This DOF is associated with volume 0 of the reference element.
\(\displaystyle l_{28}:\boldsymbol{v}\mapsto\displaystyle\int_{R}\boldsymbol{v}\cdot\left(\begin{array}{c}s_{1}\\- s_{0} - s_{2} + 1\\s_{1}\end{array}\right)\)
where \(R\) is the reference element;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(R\).

\(\displaystyle \boldsymbol{\phi}_{28} = \left(\begin{array}{c}\displaystyle 60 x \left(x + 2 y + z - 1\right)\\\displaystyle 60 y \left(- 5 x - 4 y - 5 z + 4\right)\\\displaystyle 60 z \left(x + 2 y + z - 1\right)\end{array}\right)\)

This DOF is associated with volume 0 of the reference element.
\(\displaystyle l_{29}:\boldsymbol{v}\mapsto\displaystyle\int_{R}\boldsymbol{v}\cdot\left(\begin{array}{c}- s_{1} - s_{2} + 1\\s_{0}\\s_{0}\end{array}\right)\)
where \(R\) is the reference element;
and \(s_{0},s_{1},s_{2}\) is a parametrisation of \(R\).

\(\displaystyle \boldsymbol{\phi}_{29} = \left(\begin{array}{c}\displaystyle 60 x \left(- 4 x - 5 y - 5 z + 4\right)\\\displaystyle 60 y \left(2 x + y + z - 1\right)\\\displaystyle 60 z \left(2 x + y + z - 1\right)\end{array}\right)\)

This DOF is associated with volume 0 of the reference element.