I need to write the equation given below.

I got the error:

Undefined control sequence

I have tried a lot.

LaTeX template was downloaded from the link given below.


It uses WileyNJD-v2 class file.

My code contains:



\begin{align}&{P_{{\mathop{\text{c}}},{{d1}}}}(r_{1},\phi_{1},T) ={\mathds{P}}\left[{\text{SINR} _{d1}} \geq T \right]= \mathds{P}\left[\frac{{{P_d}{d_0^{ - {\alpha _d}}}g}}{{I_{d1} + {I_{u1}} + N}} \geq T \right]\notag\\&\quad = \mathds{P}\left[g \geq \frac{{T {d_0^{{\alpha _d}}}\left(I_{d1} + {I_{u1}} + N\right) }}{{{P_d}}}\right] \notag \\&\quad \mathop = \limits^{(a)}{\mathop{\mathds{E}_{{I_{d1}},I_{u1}}}}\left[{\exp \left(\frac{{ - T {d_0^{{\alpha _d}}}(I_{d1} + {I_{u1}} + N) }}{{{P_d}}}\right)} \right] \notag\\&\quad \mathop = \limits^{(b)} {{\mathds{E}}_{I_{d1}}}\left[{\exp \left(\frac{{ - T {d_0^{{\alpha _d}}}I_{d1}}}{{{P_d}}}\right)} \right] {{\mathds{E}}_{{I_{u1}}}}\left[{\exp \left(\frac{{ - T {d_0^{{\alpha _d}}}{I_{u1}}}}{{{P_d}}}\right)} \right] \notag \\&\qquad \times \exp \left({\frac{{ - T {d_0^{{\alpha _d}}}N}}{{{P_d}}}} \right)\tag{21}\end{align}
  • off-topic: amsmath automatically loads amstext so there's no need to do it separately. Commented Sep 25, 2017 at 13:28

1 Answer 1


I changed your example to use article so I could run it



\begin{align}&{P_{{\mathop{\text{c}}},{{d1}}}}(r_{1},\phi_{1},T) =
{\mathds{P}}\left[{\text{SINR} _{d1}} \geq T \right]= \mathds{P}\left[\frac{{{P_d}{d_0^{ - {\alpha _d}}}g}}{{I_{d1} + {I_{u1}} + N}} 
\geq T \right]\notag\\
&\quad = 
\mathds{P}\left[g \geq \frac{{T {d_0^{{\alpha _d}}}\left(I_{d1} + {I_{u1}} + N\right) }}{{{P_d}}}\right] \notag \\
&\quad \mathop = 
\limits^{(a)}{\mathop{\mathds{E}_{{I_{d1}},I_{u1}}}}\left[{\exp \left(\frac{{ - T {d_0^{{\alpha _d}}}(I_{d1} + {I_{u1}} + N) }}{{{P_d}}}\right)} \right] \notag\\&\quad \mathop = 
\limits^{(b)} {{\mathds{E}}_{I_{d1}}}\left[{\exp \left(\frac{{ - T {d_0^{{\alpha _d}}}I_{d1}}}{{{P_d}}}\right)} \right] {{\mathds{E}}_{{I_{u1}}}}\left[{\exp \left(\frac{{ - T {d_0^{{\alpha _d}}}{I_{u1}}}}{{{P_d}}}\right)} \right] \notag \\
&\qquad \times \exp \left({\frac{{ - T {d_0^{{\alpha _d}}}N}}{{{P_d}}}} \right)\tag{21}\end{align}


which gives the error

! Undefined control sequence.
<argument> ...1}}}}(r_{1},\phi _{1},T) = {\mathds 
                                                  {P}}\left [{\text {SINR} _...
l.17 ...}}N}}{{{P_d}}}} \right)\tag{21}\end{align}


\mathds is for double struck letters, you could use the amsfonts version and \mathbb if you add \usepackage{amsfonts} or \mathds is from the package dsfont so add \usepackage{dsfont}


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