Here is a puzzle:
]e1 =: allsubsets 'ab'
++-+-+--+
||b|a|ab|
++-+-+--+
]e2 =: '';'b';'a';'ab'
++-+-+--+
||b|a|ab|
++-+-+--+
e1 isequalset e2
0
e1 -: e2
0
e1 = e2
1 0 0 1
I "know the answer" but don't know the cure.
For reference:
allsubsets =: 3 : 0 NB. An explicit alternative to Raul's neat form.
if. isemptyset y do. a:
else.
(#&y) &.> ( <"1 (#: i.2^#y))
end.
)
isequalset =: isin~ *. isin
isin =: *./ @ e.
I believe verb isemptyset is irrelevant and don't list it here.
Kip
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