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• Std/lists
• Union$

Std/lists/union

Theorems about union$ in the std/lists library.

Definitions and Theorems

Theorem: true-listp-of-union-equal

(defthm true-listp-of-union-equal
        (equal (true-listp (union-equal x y))
               (true-listp y)))

Theorem: true-listp-of-union-equal-type

(defthm true-listp-of-union-equal-type
        (implies (true-listp y)
                 (true-listp (union-equal x y)))
        :rule-classes :type-prescription)