span> <span class="string">PSI</span> <span class="string">dPSI</span> <span class="string">ddPSI</span>

<span class="comment">% Alternative velocity related variables: Side slip angle and speed</span>
<span class="comment">% Alternative variables (symfun)</span>
syms <span class="string">ALPHAT_t(t)</span> <span class="string">VT_t(t)</span>
<span class="comment">% Alternative variables and time derivatives (sym)</span>
syms <span class="string">VT</span> <span class="string">ALPHAT</span> <span class="st