Let $\displaystyle f_1=2xy^2-x,f_2=3x^2y-y-1$. Consider the order grlex and find a polynomial of the ideal generated by $\displaystyle f_1$ and $\displaystyle f_2$ such that divided by $\displaystyle f_1$ or by $\displaystyle f_2$ its rest is different from 0.

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