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A quasi norm is a non-negative function $||.||$ on a linear space
$\mathcal{X}$ satisfying the same axioms as a norm except for the
triangle inequality, which is replaced by the weaker condition
that ``there is a constant $K \geq 1$ such that $||x+y|| \leq
K(||x|| + ||y||)$ for all $x, y \in \mathcal{X}$". In this paper,
we prove the Hyers-Ulam-Rassias stability of linear mappings in
quasi-Banach modules associated to the Cauchy functional equation
and a generalized Jensen functional equation.
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