nice Linda, 1 2 2 2 4 5 (~.@] #~ #/.~@] <. +/"1@( =/~ ~.)) 4 2 2 4 3 5 4 2 2 5
________________________________ From: Linda Alvord <[email protected]> To: "[email protected]" <[email protected]> Sent: Tuesday, October 30, 2018 1:16 PM Subject: Re: [Jprogramming] Intersection and Union of (multi)sets A=: 1 2 3 3 3 B=:3 3 3 3 3 4 5 6 A IS_reb B 3 3 3 A=:1 2 3 3 3 B=:3 3 3 3 3 4 5 6 us=: 13 :'(+./"2 x=/x,y)#x,y' A us B 1 2 3 3 3 3 3 3 3 3 is=: 13 :'(+."1/x=/y)#y' A is B 3 3 3 3 3 Linda -----Original Message----- From: Programming <[email protected]> On Behalf Of Don Guinn Sent: Tuesday, October 30, 2018 12:32 PM To: Programming forum <[email protected]> Subject: Re: [Jprogramming] Intersection and Union of (multi)sets Yes. The killer is p: . But this got me curious. I finally remembered that the inverse of q: was */ but I was surprised to find that the inverse of */ was q: */ b._1 q: */^:_1]12 2 2 3 But this is an error. +/ b._1 |domain error | +/b._1 Granted, the inverse of sum has no meaning. And the inverse of */ to be q: makes a useful tool. But information is lost. (]&.(*/))3 4 2 2 3 So I was thinking that */^:_1 should be an error. Then again, *: b._1 %: (]&.*:)_4 4 4 4 ---------------------------------------------------------------------- For information about J forums see https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.jsoftware.com%2Fforums.htm&data=02%7C01%7C%7Cf37820c18ca64486fce808d63e85341c%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636765139156867865&sdata=PXJVvRemk4pIj9%2B1AwEwBDX9W4vA0b3bEyZpFJp%2FjNs%3D&reserved=0 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
