Foundations of Functional Roots: The Lambda Calculus Legacy
A century after Church introduced lambda calculus in the 1930s, its minimalist elegance remains the silent engine of modern programming. The calculus defines computation through three primitives: variables (x), lambda abstraction (λx.M), and application (M N). This trio enables pure functional expression—computation as pure function evaluation, with no side effects or mutable state. Despite its simplicity, lambda calculus is **computationally universal**, meaning any recursive algorithm can be expressed through its reduction rules. This universality mirrors how complex software emerges from simple, composable functions—each layer built from minimal, predictable building blocks.


