Comment NB. This is a single line comment, check regions overlapping priority: 1 2.3 +/ &. 'quoted text' NB.( NB. This is a foldable multi line comment NB.) String literal '' '''' 'This is quoted text' 'And this '' and this NB. and this' 'Yet another quoted text' Numeric literal 12 34.56 _7.89 1e2 1.2e3 _. _ __ 123j_456 2b111.111 1r23 123456x 1.2e3j4.5e6 _j_ __j_ _.j_. _j3p4j_. Parenthesis ( ) Adverb ~ / \ /. \. } b. f. M. t. t: Conjuction ^: . .. .: : :. :: ;. !. !: " ` `: @ @. @: & &. &: &.: d. D. D: H. L: S: T. Control assert. break. case. catch. catchd. catcht. continue. do. else. elseif. end. fcase. for. for_abc. goto_abc. if. label_abc. return. select. throw. try. while. whilst. Copula a =: 123 (a) =: 123 (a;b;c) =: 123 'a b c' =: 123 'a b c' =. '123' '`a b c' =. '123' 'a' =: 123 ('a';'b';'c') =: 123 Explicit argument x y m n u v x. y. m. n. u. v. Noun a. a: Verb = < <. <: > >. >: _: + +. +: * *. *: - -. -: % %. %: ^ ^. $ $. $: ~. ~: | |. |: , ,. ,: ; ;: # #. #: ! /: \: [ [: ] { {. {: {:: }. }: ". ": ? ?. A. C. e. E. i. i: I. j. L. o. p. p.. p: q: r. s: u: x: _9: _8: _7: _6: _5: _4: _3: _2: _1: 0: 1: 2: 3: 4: 5: 6: 7: 8: 9: Combined for_abc. i. 5 do. 55 return. end. a=. b =: 123 +/ # i. 10 123 'qwerty' a_b =: '123' [ c__d =. 4 : 0 NB. foldable definition begins x +/ y ) e__12 =: define NB. foldable definition begins if. x do. NB. inner foldable region begins y=. y + x NB. comment after code x +/ y else. NB. inner foldable region begins y +/ y end. )