The keys in a hash are always strings. You cannot use an array slice as a hash key. You have to join the list to form a string: 
    exists $hash{ join q(), @array[3 .. $end] }

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لսႽ† ᥲᥒ⚪⟊Ⴙᘓᖇ Ꮅᘓᖇ⎱ Ⴙᥲ𝇋ƙᘓᖇ

In reply to Re^3: Print/Lookup from array element to another array element by choroba
in thread Print from array element to another array element by Dr Manhattan

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