# Article

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Keywords:
semilat\/tice; lat\/tice; antitone involution; congruence permutability; weak regularity
Summary:
We study \$\vee\$-semilat\/tices and lat\/tices with the greatest element 1 where every interval [p,1] is a lat\/tice with an antitone involution. We characterize these semilat\/tices by means of an induced binary operation, the so called sectionally antitone involution. This characterization is done by means of identities, thus the classes of these semilat\/tices or lat\/tices form varieties. The congruence properties of these varieties are investigated.
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