resultant[i (x^2 - 1) x^3 + 2 i (x^6- 1)(x^2+1) + y (x^2 + 1) x^3, x^12+x^11+x^10+x^9+x^8+x^7+x^6+x^5+x^4+x^3+x^2+x+1,x]

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