theorem
Verification.gaussian_normalCDF_product_integral
{r : ℝ}
(hr : r ∈ Set.Icc (-1) 1)
(a b c : ℝ)
(hb : 0 < b)
(hc : 0 < c)
:
∫ (p : ℝ × ℝ), ↑(ProbabilityTheory.cdf (ProbabilityTheory.gaussianReal 0 1)) (a * p.1 / b) * ↑(ProbabilityTheory.cdf (ProbabilityTheory.gaussianReal 0 1))
(a * (r * p.1 + √(1 - r ^ 2) * p.2) / c) ∂(ProbabilityTheory.gaussianReal 0 1).prod (ProbabilityTheory.gaussianReal 0 1) = 1 / 4 + Real.arcsin (r * a ^ 2 / (√(a ^ 2 + b ^ 2) * √(a ^ 2 + c ^ 2))) / (2 * Real.pi)
theorem
Verification.gaussian_cdf_product_integral
{r : ℝ}
(hr : r ∈ Set.Icc (-1) 1)
(a b c : ℝ)
(hb : 0 < b)
(hc : 0 < c)
:
∫ (x : EuclideanSpace ℝ (Fin 2)), ↑(ProbabilityTheory.cdf (ProbabilityTheory.gaussianReal 0 1)) (a * x.ofLp 0 / b) * ↑(ProbabilityTheory.cdf (ProbabilityTheory.gaussianReal 0 1))
(a * x.ofLp 1 / c) ∂ProbabilityTheory.multivariateGaussian 0 (bivariateCorrelation r) = 1 / 4 + Real.arcsin (r * a ^ 2 / (√(a ^ 2 + b ^ 2) * √(a ^ 2 + c ^ 2))) / (2 * Real.pi)