The obvious tacit expression would be the one generated by 13 :'u1(u2(u3(u4(y))))'
But note that this may generate different expressions, depending on the values of u1, u2, u3 and/or u4. (The default behavior, if they are not defined, is to assume that they are all verbs.) Thanks, -- Raul On Sat, Aug 6, 2016 at 4:02 PM, Erling Hellenäs <[email protected]> wrote: > u1(u2(u3(u4(y)))) was the mathematical description of the strawman > algorithm. We are still in a discussion about tacit J. The expression you > are opposing is this one: > > > "As far as I can understand the pattern of the strawman, [: u1 [:u2 [: u3 [: > u4 ] , is the only expression in tacit J with the meaning of 4 monadic > verbs ux in sequence. All other similar expressions have a more complex > meaning. Correct me if I'm wrong." > > Bob Thierrault says: > > I believe it could also be expressed as > > u1 @: u2 @: u3 @: u4 @: ]"_ > > Cheers, bob > > You say he is right: > > "Yes, and the @:]"_ is redundant for any and all verbs u1 u2 u3 and u4. > And ([: u1 [:u2 u3@:u4) is another example equivalent..." > > I think I proved you both wrong with this: > > There is a considerable difference in memory allocation indicating > differences between these expressions. If the first version creates > three copies, the second seems to create five. > > > ts'([: - [: - [: - [: - ])i. 100000000' > > 1.45991 3.22123e9 > > ts'(- @: - @: - @: - )i. 100000000' > > 1.48942 5.36871e9 > > And this: > > Its is some redundant calls to the @: conjunction that makes the difference? > > ts'(- @: - @: - @: - )i. 100000000' > > 1.56681 5.36871e9 > > c=: 2 :(':';'[: u v') > > ts'(- c - c - c - )i. 100000000' > > 1.56479 5.36871e9 > > It is unclear which tacit J expression you mean by u1(u2(u3(u4(y)))). > > /Erling > > > > On 2016-08-05 22:22, Raul Miller wrote: >> >> If you want the algorithm of u1(u2(u3(u4(y)))) and not any expression >> with the same result, then you should be using u1(u2(u3(u4(y)))) and >> not some other expression. >> >> That said, you might want to wrap it in verb def '' (with the >> expression going inside the quotes) so that you can have a verb >> definition. >> >> Thanks, >> > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
