transformation rule

In logic, a transformation rule, also known as a rule of deduction, establishes the conditions under which one statement can be validly derived from other statements. This process is fundamental to drawing conclusions from given information or premises, a concept known as inference. Logic, in its broadest sense, is the study of correct reasoning, focusing on how inferences are made.123

A key aspect of logic involves formation rules, which dictate how permissible combinations of symbols can be constructed to form statements or formulas within a formalized language or calculus. These rules are distinct from transformation rules, which govern how statements can be manipulated or deduced. For instance, in a formal system, formation rules define what constitutes a valid term or sentence, while transformation rules allow for the derivation of new truths from existing ones.45