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Aug 6, 2023, 4:50:20 PM8/6/23

to sage-support

Consider :

sage: reset() sage: z=var("z") sage: Eq=(3+4*I)^2-2*(z.conjugate())==z ; Eq -2*conjugate(z) + 24*I - 7 == z sage: Sol=solve(Eq, z) ; Sol [z == (8*I - 7/3)] sage: Eq.subs(Sol[0]) (40*I - 7/3) == (8*I - 7/3) sage: bool(Eq.subs(Sol[0])) Falsewhich annoys me *immensely*. It reeks of conjugate() error, which, AFAICT is ginac territory…

However :

sage: E2=(Eq.lhs()-Eq.rhs()).subs(z=x+I*y) ; E2 -3*x + I*y + 24*I - 7 sage: S2=solve([E2.real(), E2.imag()], [x, y]) ; S2 [[x == (-7/3), y == -24]] sage: E2.subs(S2[0]) 0 sage: Eq.subs(z==x+I*y).subs(S2[0]) (-24*I - 7/3) == (-24*I - 7/3)This failure to solve a *simple* equation on complexes is troubling. Re-reading myself did not led me to “obvious” problems.

Does this deserve a critical ticket ?

BTW, there is currently no *free* alternative :

HTH,

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