The concept establishes the formal syntactic rules for invoking functions within a procedural and object-oriented programming paradigm, defining the structural relationship between a callable identifier, required argument expressions, and optional keyword mappings. It operates within the domain of computer science syntax and formal language theory, specifically addressing the parsing and semantic interpretation of function calls as a mechanism for executing procedures or methods. This abstract theory governs the transition from static source code to dynamic execution by enforcing strict ordering and binding contexts necessary for parameter passing and return value propagation.
Prerequisite chain context: requires Function Definition Syntax in Python.