Algebra, analysis and inequality signs involving modulus signs

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How do you derive that | |x|-|y| |<= |x-y|

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If you already have the triangle inequality -

$$ |x| = |x-y+y| \leq |x-y| + |y|. $$

Subtract from both sides to conclude that

$$ |x| - |y| \leq |x-y|. $$