isabelle/valid/mathd_algebra_393.thy (13 lines of code) (raw):
(*
Authors: Wenda Li
*)
theory mathd_algebra_393
imports Complex_Main "HOL-Computational_Algebra.Computational_Algebra"
begin
theorem mathd_algebra_393:
fixes \<sigma>::"real \<Rightarrow> real"
assumes "bij \<sigma>"
and "\<forall> x. \<sigma> x = 4 * x^3 + 1"
shows "inv \<sigma> 33 = 2"
sorry
end