Where does scope collide?

In logic and the study of meaning, the scope of an operator, quantifier, or negation is the part of an expression over which it takes effect and which it controls. When a sentence like every student did not pass can be read two ways, the readings differ only in whether every or not governs the other, that is, in their relative scope. Szabolcsi's 2010 Quantification surveys how the scope of quantifiers is assigned across languages and why one string of words can carry several meanings. The referent here is an abstract relation of control between parts of an expression, not a region of running code, the agreed boundary of a project, or a viewing instrument.[1]

Unit

One operator's domain of control over an expression

Recovery means

Not applicable

Measured by

Diagnosed by paraphrase and truth conditions, and formalised in logical form by the relative order of the operators

In a programming language, the scope of a name is the region of the program in which that name refers to a particular binding and can be used to reach it. Under lexical, also called static, scope the region is fixed by where the name is written, nested block within nested block, while under dynamic scope it depends on the order in which code runs. Landin's 1964 The Mechanical Evaluation of Expressions introduced the environment, the structure that binds names to values and fixes where each binding is visible, which underlies the modern lexical account of scope. The referent is a region of a program where a name is valid, not a control relation in a sentence, a project's boundary of work, or an optical instrument.[2]

Unit

The region of program text where a name binding is valid

Recovery means

Not applicable

Measured by

Determined by the language's scoping rules and resolved by the compiler or interpreter when a name is looked up