\[ \left \{x'(t)=y(t)-z(t),y'(t)=x(t)+y(t),z'(t)=x(t)+z(t)\right \} \] ✓ Mathematica : cpu = 0.0088684 (sec), leaf count = 105
\[\left \{\left \{x(t)\to c_2 \left (e^t-1\right )+c_3 \left (1-e^t\right )+c_1,y(t)\to c_1 \left (e^t-1\right )+c_2 \left (e^t t+1\right )+c_3 \left (-e^t t+e^t-1\right ),z(t)\to c_1 \left (e^t-1\right )+c_2 \left (e^t t-e^t+1\right )+c_3 \left (-e^t t+2 e^t-1\right )\right \}\right \}\] ✓ Maple : cpu = 0.092 (sec), leaf count = 43
\[\{\{x \left (t \right ) = c_{2} {\mathrm e}^{t}+c_{3}, y \left (t \right ) = -c_{3}+\left (c_{2} t +c_{1}\right ) {\mathrm e}^{t}, z \left (t \right ) = -c_{3}+\left (c_{1}+c_{2} \left (t -1\right )\right ) {\mathrm e}^{t}\}\}\]