Abstract Loday's 1-cat group definition plays very powerful role in making
some new applications to crossed module due to Whitehead. There
are many applications of cat1-groups such as
cat1-polygroups and pullback cat1-polygroups. The importance of hypergroups come from the
properties of hypergroups such that hypergroups in the sense of
Marty do not have identity element, inverse element and they are
generalization of the well known groups. In this paper, we introduce the concept of cat1-hypergroups, their examples and some related properties.
Also, we investigate pullback cat1-hypergroups and properties such as: every cat1-group is a cat1-hypergroup; construction of a cat1-group from a crossed module of hypergroups and vice versa. Finally, we present the definition of pullback cat1-hypergroups and some of their properties. 
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