An Eight-Step Proof of the Riemann Hypothesis in △-Ontology

Within the framework of △-ontology, where the primitive element is the infinium ℑ = △₁ₓ₁ (a right isosceles triangle with legs 1 and hypotenuse √2), a complete formal proof of the Riemann Hypothesis is constructed. The proof is structured as a sequence of eight logically independent steps: from the construction of the shift operator U and the Laplacian Δ, through the combinatorial theory of △-mosaics and the connection with the Euler product, to the derivation of the critical line Re(s) = 1/2. Each step is accompanied by an explanatory commentary and an explicit status of its formal verification. All components of the proof are fully formalized in Lean 4.