%0 Journal Article %T SEQUENTIALLY COMPACT S-ACTS %J Journal of Algebraic Systems %I Shahrood University of Technology %Z 2345-5128 %A Barzegar, H. %D 2018 %\ 01/01/2018 %V 5 %N 2 %P 111-125 %! SEQUENTIALLY COMPACT S-ACTS %K sequentially compact‎ %K ‎ ‎$f$-pure‎ ‎injective %K injective S-act %R 10.22044/jas.2017.4357.1218 %X ‌‌The investigation of equational compactness was initiated by‌ ‌Banaschewski and Nelson‌. ‌They proved that pure injectivity is‌ ‌equivalent to equational compactness‌. ‌Here we define the so‌ ‌called sequentially compact acts over semigroups and study‌ ‌some of their categorical and homological properties‌. ‌Some‌ ‌Baer conditions for injectivity of S-acts are also presented‌. %U https://jas.shahroodut.ac.ir/article_1095_09001f39c3743b6d98c90f11286807eb.pdf