English
If z and w are complex numbers and a certain nondegeneracy condition holds (z = 0 implies w.re = 0 implies w = 0), then the norm of z^w equals the real part of w applied to the log magnitude of z adjusted by the argument of z and the imaginary part of w:
Русский
Если z и w — комплексные числа и выполняется ненулевая условие, то нормa z^w равна |z|^{Re w} / exp( Arg z · Im w).
LaTeX
$$$$ \\| z^w \\| = \\| z \\|^{\\Re w} \\/ e^{\\mathrm{Arg}(z) \\cdot \\Im w}, \\quad z = 0 \\Rightarrow w\\ \\text{условие}.$$$$
Lean4
@[reassoc (attr := simp)]
theorem w_prod_fst {A B : CostructuredArrow (S.prod S') (T, T')} (f : A ⟶ B) : S.map f.left.1 ≫ B.hom.1 = A.hom.1 :=
congr_arg _root_.Prod.fst (CostructuredArrow.w f)