The interpretation of a formal theory of logic is dependent on interpreting the sentences of theorems of that theory in a way that is consistent with the syntax and semantics of the theory.

In order for a theory of logic to be meaningful, it is necessary for its sentences and theorems to be logically consistent with each other. This means that the sentences must be constructed in accordance with the rules and syntax of the theory, and that the interpretation assigned to the symbols and operators in the theory must be consistent with the logical relationships between these symbols and operators.

For example, if a theory of logic includes the symbol for negation (~), it must be interpreted in a way that is consistent with the logical relationship between negation and other logical operators such as conjunction and disjunction. Similarly, if a theory includes the quantifier "forall", it must be interpreted in a way that is consistent with the semantics of universal quantification.

In order to ensure that the interpretation of a theory of logic is consistent with its syntax and semantics, it is necessary to validate the sentences and theorems produced by the theory against the theoretical set of sentences that may be produced by that theory. This can involve various techniques such as model theory, proof theory, or semantics, which are used to validate the logical consistency of the theory and ensure that its sentences and theorems are interpretable in a meaningful way.