Reflection positivity: G(x,y) = exp(-m(x+y)) = K(x)·K(y) is rank-1 PSD

Sympy-exact symbolic witness of reflection-positivity via a rank-1 separable Gaussian-propagator construction. Setup: m, x, y ∈ R₊ (sp-symbols positive). Reflection-positive kernel G(x,y) = exp(-m·(x+y)) admits exact separation G(x,y) =…