Deterministic COBOL Transpilation

Technical Thesis on Bit-Exact Migration to Five Modern Languages

Introduction

This document provides a comprehensive record of transpiling a legacy COBOL batch program (1988 Regional Bank system) into Java, Rust, Go, C#, and Kotlin. In an era dominated by probabilistic AI, this project adheres strictly to "100% Determinism." Every calculation, including fixed-point arithmetic and rounding, is verified to be bit-exact against the original mainframe execution.

Core Specifications

Input Dialects	IBM Enterprise COBOL / Unisys MCP COBOL
Output Targets	Java 21, Rust 1.75+, Go 1.21+, C# 12, Kotlin 1.9 (WASM compatible)
Key Technology	Slot-based Intermediate Representation (Slot IR) & PSDP
Verification	180-cell validation matrix (18 cases × 5 languages × 2 dialects)

Technical Document (PDF Edition)
280 Pages | Release: April 2026

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