simp at hpmag
case mk
pangle pmag : ℝ
hpmag : { angle := pangle, magnitude := pmag }.magnitude > 0
hpangle1 : -(Real.pi / 2) < { angle := pangle, magnitude := pmag }.angle
hpangle2 : { angle := pangle, magnitude := pmag }.angle < Real.pi / 2
⊢ Complex.toPolar (Polar.toComplex { angle := pangle, magnitude := pmag }) = { angle := pangle, magnitude := pmag }
case mk
pangle pmag : ℝ
hpangle1 : -(Real.pi / 2) < { angle := pangle, magnitude := pmag }.angle
hpangle2 : { angle := pangle, magnitude := pmag }.angle < Real.pi / 2
hpmag : 0 < pmag
⊢ Complex.toPolar (Polar.toComplex { angle := pangle, magnitude := pmag }) = { angle := pangle, magnitude := pmag }