CN-LEAGUE 2006 Problem 3

Solve the system of equations in real numbers: $\begin{cases} x-y+z-w=2 x^2-y^2+z^2-w^2=6 x^3-y^3+z^3-w^3=20 x^4-y^4+z^4-w^4=66 \end{cases}$

Dataset text AI-MO AoPS. Quoted with source.

Solutions

No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.