# Essays/Insert

/ is an adverb and u/y applies the dyad u between the items of y . For example, +/y computes the sum. This differs from conventional mathematical notation in making explicit that there is an adverb and that no special symbol is required for u/ for each function u . For example, in conventional notation sum is $\sum$ and product is $\prod$.
 +/ y sum */ y product; (!n) = */1+i.n -/ y alternating sum; e.g. -/ z (^%!@]) 1+2*i.n approximates sin z >./ y maximum <./ y minimum (+%)/ y continued fraction; e.g. (+%)/n\$1 approximates $\phi$ +%/ y generalized continued fraction; e.g. +%/ 3,6,.~*:1+2*i.n approximates $\pi$ +`*/ }:,x,.y computation of x p. y by Horner's rule y {~ /:@/:@,/ ((-i.)#y)#:x computation of x A. y ; see Permutation Index (<@i.@>:@I.~ C. ,)/ y an O(n^2^) sort of vector y *./ #&> C. p the size of the subgroup generated by permutation p *./ b Are all of b true? +./ b Is any of b true? ~:/ b 1 iff the number of 1s is odd =/ b 1 iff the number of 0s is even