I produced the verbs below to explore ^:_1 and &. with assigned inverses.
They display whether they were called as a monad or a dyad. Each produce a result containing their arguments. Something doesn't seem quite right with the last example. A =: 3 : 0 'A-y' (1!:2)2 'A-y';<y : 'x-A-y'(1!:2)2 x;'x-A-y';<y ) B =: 3 : 0 'B-y' (1!:2)2 'B-y';<y : 'x-B-y'(1!:2)2 x;'x-B-y';<y ) C =: (A :. B) "> NB. C has the same rank as > 1 A 2 x-A-y +-+-----+-+ |1|x-A-y|2| +-+-----+-+ A 3 A-y +---+-+ |A-y|3| +---+-+ 10 B 20 x-B-y +--+-----+--+ |10|x-B-y|20| +--+-----+--+ B 30 B-y +---+--+ |B-y|30| +---+--+ 100 C 200 x-A-y +---+-----+---+ |100|x-A-y|200| +---+-----+---+ C 300 A-y +---+---+ |A-y|300| +---+---+ 1000 ;&.C 2000 A-y A-y B-y B-y B-y +---+------------+ |B-y|+----------+| | ||+---+----+|| | |||A-y|1000||| | ||+---+----+|| | |+----------+| +---+------------+ |B-y|+---+ | | ||A-y| | | |+---+ | +---+------------+ |B-y|+----+ | | ||2000| | | |+----+ | +---+------------+ 100 (C^:_1) 200 |domain error | 100 (C^:_1)200 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
