NOT.2:4.3 - Define which declaration or external value a reference uses

Identify the constructions that introduce local names and the parts in which those names apply. State how a name occurrence reaches its declaration or an input supplied from outside. The visible extent of a box or line becomes a scope boundary only through an established rule of the notation.

For a notation with lexical scope, a common rule resolves a name at its nearest enclosing declaration with that name; if there is none, the value must come from the declared external context. Adopt that rule only when it fits the intended interpretation. Other schemes can make references available through earlier statements, explicit identifiers or connections. Define their resolution accordingly.

Trace the references in one expression with repeated names and one expression with a free input. Here a free input is one whose value must be supplied from outside the expression. If insertion, copying or renaming changes which declaration an occurrence reaches, expose that change before treating the result as equivalent. NOT.4 develops transformations that preserve the intended use.

For a reusable component, distinguish its locally introduced names from the inputs and results made available at its boundary. Compose components by those boundary references. A displayed label can be repeated without identifying its occurrences as the same declaration; the reference rule must settle that question.