2025/10/18 by Jain, Moida Praneeth, Venkatesh Choppella, Choppella, Venkatesh
Computer Science · #Computational Physics and Python Applications #F.1.1 #F.3.2 #FOS: Computer and information sciences #Programming Languages (cs.PL) #Software Engineering Research #Teaching and Learning Programming
paper · pdf · doi:10.48550/arxiv.2510.16594
openalex publication_date 2025/10/18 · openalex created_date 2025/10/22 · openalex updated_date 2026/07/28
Misconceptions about program execution hinder many novice programmers. We introduce SimpliPy, a notional machine designed around a carefully chosen Python subset to clarify core control flow and scoping concepts. Its foundation is a precise operational semantics that explicitly tracks source code line numbers for each execution step, making the link between code and behavior unambiguous. Complementing the dynamic semantics, SimpliPy uses static analysis to generate Control Flow Graphs (CFGs) and identify lexical scopes, helping students build a structural understanding before tracing. We also present an interactive web-based debugger built on these principles. This tool embodies the formal techniques, visualizing the operational state (environments, stack) and using the static CFG to animate control flow directly on the graph during step-by-step execution. SimpliPy thus integrates formal semantics, program analysis, and visualization to offer both a pedagogical approach and a practical demonstration of applying formal methods to program understanding.