nLab
structural rule

Idea

The structural rules of a logic or deductive system are those rules which make no reference to logical operators but only to the unstructured premises of a deduction.

Examples

• the weakening rule,
• the contraction rule,
• the exchange rule,
• the identity rule?,
• the cut rule?.

Related pages

• substructural logic is logic in which one or more structural rules are omitted.