Overview:A-calculus as a language ·Syntax How to write a program? ·Keyword“饩"for defining functions 。Semantics How to describe the executions of a program? Calculation rules called reduction ·Others Type system(next class) Model theory(not covered) ●… Overview: -calculus as a language • Syntax • How to write a program? • Keyword “” for defining functions • Semantics • How to describe the executions of a program? • Calculation rules called reduction • Others • Type system (next class) • Model theory (not covered) • …