# Article

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Keywords:
{\it Bloch} space; composition operator; essential norm; difference; compactness
Summary:
Let $\varphi$ and $\psi$ be holomorphic self-maps of the unit disk, and denote by $C_\varphi$, $C_\psi$ the induced composition operators. This paper gives some simple estimates of the essential norm for the difference of composition operators $C_\varphi -C_\psi$ from Bloch spaces to Bloch spaces in the unit disk. Compactness of the difference is also characterized.
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