A more thorough explanation:

Definition: Antecedent basis is a term used in patents to refer to a general word or phrase that is introduced in a claim or description, and to which a later specific word or phrase must refer. If the latter word is not clearly connected to its antecedent, the wording becomes ambiguous, and claims will be rejected as impermissibly vague or indefinite.

Example: A patent claim may state, "A device comprising a handle and a blade, said blade being made of steel." In this example, "said blade" refers back to "blade," which is the antecedent basis. The use of "said" indicates that the blade being referred to is the one previously mentioned.

Explanation: The example illustrates how the antecedent basis is used to ensure clarity and specificity in patent claims. By establishing a general term or phrase and then referring back to it with a specific term or phrase, the patent claim becomes more precise and less open to interpretation. This is important in patent law, where the language used in claims can have a significant impact on the scope of the patent and its enforceability.