Are the numbers amicable?
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QfÆṣ⁼


A monadic link taking a list of two integers which returns 1 if they are a pair of amicable numbers and 0 otherwise.

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How?

QfÆṣ⁼ - Link: pair of numbers L, [a, b]   e.g. [220,284]  or [6,6]  or [6,11]  or [100,52]
Q     - de-duplicate L                         [220,284]     [6]       [6,11]     [100,52]
  Æṣ  - proper divisor sum of L (vectorises)   [284,220]     [6]       [6,1]      [117,46]
 f    - filter keep left if in right           [220,284]     [6]       [6]        []
    ⁼ - equal to L?                            1             0         0          0