\[ \left \{x'(t)=-x(t) y(t)^2+x(t)+y(t),y'(t)=x(t)^2 y(t)-x(t)-y(t),z'(t)=y(t)^2-x(t)^2\right \} \] ✗ Mathematica : cpu = 0.700261 (sec), leaf count = 0
DSolve[{Derivative[1][x][t] == x[t] + y[t] - x[t]*y[t]^2, Derivative[1][y][t] == -x[t] - y[t] + x[t]^2*y[t], Derivative[1][z][t] == -x[t]^2 + y[t]^2},{x[t], y[t], z[t]},t]
, could not solve
DSolve[{Derivative[1][x][t] == x[t] + y[t] - x[t]*y[t]^2, Derivative[1][y][t] == -x[t] - y[t] + x[t]^2*y[t], Derivative[1][z][t] == -x[t]^2 + y[t]^2}, {x[t], y[t], z[t]}, t]
✗ Maple : cpu = 0. (sec), leaf count = 0
dsolve({diff(x(t),t) = -x(t)*y(t)^2+x(t)+y(t), diff(y(t),t) = x(t)^2*y(t)-x(t)-y(t), diff(z(t),t) = y(t)^2-x(t)^2})
, result contains DESol or ODESolStruc
\[[\{x \left (t \right ) = 0\}, \{y \left (t \right ) = 0\}, \{z \left (t \right ) = c_{1}\}]\]