# adverb projection/composition questions **URL:** https://forum.kx.com/t/adverb-projection-composition-questions/12046 **Category:** Community Support **Tags:** kdb-and-q **Created:** [August 3, 2020, 8:15am UTC](https://forum.kx.com/t/adverb-projection-composition-questions/12046 "2020-08-03T08:15:00Z") **Posts on this page:** 1 **Page:** 1
### Author: ![erik\_friis1](https://avatars.discourse-cdn.com/v4/letter/e/ee59a6/32.png) [@erik\_friis1](https://forum.kx.com/u/erik_friis1) #### Post date: [August 3, 2020, 8:15am UTC](https://forum.kx.com/t/adverb-projection-composition-questions/12046/1 "2020-08-03T08:15:00Z")
Reading up on compositions and I see that one is created with the prefix form: '[f;g] Is there no infix form in q? f’g signals an exception. In k4 however both of these work–I would have expected them to be equivalent but they are not.   f’g {x+y}'[{x\*y}]  '[f;g] {x+y}{x\*y} Furthermore, why does ‘[’] have a type of 106 when ’ is not a function and is expecting a function argument–why is it not a projection? ‘’ is not a derived function as far as I can tell. @ (‘[’]) 106h Also please tell me why the ' gets replaced in the first expression. (‘[’])[+/] +/' (‘[’[+/]]) +/‘’ Finally from an internal execution point of view (not result), is there any difference between these two expressions: q)(+/‘’)((1 2;3 4);(5 6 7;8 9 10)) 3 7 18 27 q)(‘[’;'][+/])((1 2;3 4);(5 6 7;8 9 10)) 3 7 18 27 Thanks for any insight.