8.1. GLOSSARY¶

alpha（阿尔法）¶

The name of the Greek letter \(\alpha\) (lowercase) or \(A\) (uppercase), corresponding to the letter “a”.

binding occurrence（绑定出现）¶

A binding occurrence is the place in a program where a variable is bound to its name (or identifier). In modern programming languages, a binding occurrence is the same as a declaration of the variable. In lambda calculus, a binding occurrence for, say, the variable \(x\), is any sub-expression equal to \(\lambda x.\)

bnf grammar（BNF 文法）¶

A BNF grammar is…

bound（绑定的）¶

In a lambda expression, a variable occurrence is bound or occurs bound if it belongs to the scope of a binding occurrence of that variable.

free（自由的）¶

In a lambda expression, a variable occurrence is free or occurs free if it is not bound in that expression.

function abstraction（函数抽象）¶

In lambda calculus, a function abstraction (or lambda abstraction) is synonymous with a function definition that contains the name of the formal parameter and the body of the function.

lambda（拉姆达）¶

The name of the Greek letter \(\lambda\) (lowercase) or \(\Lambda\) (uppercase), corresponding to the letter “L”.

lambda abstraction（lambda 抽象）¶

Synonym for function abstraction.

scope（作用域）¶

Abbreviation for variable scope

variable capture（变量捕获）¶

A free variable occurrence is captured when it becomes bound following the renaming of some other variable occurrence.

variable scope（变量作用域）¶

The scope of a variable declaration (or binding occurrence) in a program is the collection of all parts of the program (that is, the lines of code) in which this variable is accessible via its name or identifier.