# sv/:string vs. sv string/:
**URL:** https://forum.kx.com/t/sv-string-vs-sv-string/11497
**Category:** Community Support
**Tags:** kdb-and-q
**Created:** [February 18, 2017, 7:07am UTC](https://forum.kx.com/t/sv-string-vs-sv-string/11497 "2017-02-18T07:07:00Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@ag12](https://forum.kx.com/u/ag12)
#### Post date: [February 18, 2017, 7:07am UTC](https://forum.kx.com/t/sv-string-vs-sv-string/11497/1 "2017-02-18T07:07:00Z")
`q)a`a`b`c`d`e`f`g`h`i`j`kq)m:0N 3#aq)m`a`b`c`d`e`f`g`h`i`j`kq)q)"+" sv/:string each m"a+b+c""d+e+f""g+h+i""j+k"q)q)/ why doesn't this work?q)"+" sv string/:m'/: [0] "+" sv string/:m ^`
---
### Author:  [@effbiae](https://forum.kx.com/u/effbiae)
#### Post date: [February 18, 2017, 10:48am UTC](https://forum.kx.com/t/sv-string-vs-sv-string/11497/2 "2017-02-18T10:48:00Z")
q has Noun, Adverb and Verb
it seems that q allows NNA as in "+"sv/:
but not NA as in string/:
it does allow NVA as in string@/:
N and V are terms, so it seems q allows NtA
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### Author:  [@Davide\_Corti1](https://forum.kx.com/u/Davide_Corti1)
#### Post date: [February 18, 2017, 12:00pm UTC](https://forum.kx.com/t/sv-string-vs-sv-string/11497/3 "2017-02-18T12:00:00Z")
It has to do with the arity of the verb or function.
Adverbs such as “each-both”, “each left” and “each right” are supposed to be applied to dyadic verbs or functions (e.g., sv).
The equivalent adverb for monadic verbs of functions (e.g., string) is “each”.
string@/:m works because “@” in this case is applied in its dyadic form to the arguments “string” and “m”.
HTH,
Davide Corti | KDB+ Engineer | **Kx** | +44-7926-223284 | dcorti@kx.com
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### Author:  [@effbiae](https://forum.kx.com/u/effbiae)
#### Post date: [February 18, 2017, 12:19pm UTC](https://forum.kx.com/t/sv-string-vs-sv-string/11497/4 "2017-02-18T12:19:00Z")
\>supposed to be applied to dyadic verbs or functions
q)+/1 2 3
'/
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### Author:  [@Davide\_Corti1](https://forum.kx.com/u/Davide_Corti1)
#### Post date: [February 20, 2017, 9:18pm UTC](https://forum.kx.com/t/sv-string-vs-sv-string/11497/5 "2017-02-20T21:18:00Z")
Hi Jack,
The adverb you are using in this case is “over”.
To apply it to your last example, you need brackets:
q)(+/)1 2 3
6
The adverb we were considering previously is “each-right”.
You can use it with “+” for instance as follows:
q)1+/:1 2 3
2 3 4
q)1 2+/:4 3 2
5 6
4 5
3 4
Regards,
Davide Corti | KDB+ Engineer | **Kx** | +44-7926-223284 | dcorti@kx.com
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### Author:  [@effbiae](https://forum.kx.com/u/effbiae)
#### Post date: [February 20, 2017, 11:52pm UTC](https://forum.kx.com/t/sv-string-vs-sv-string/11497/6 "2017-02-20T23:52:00Z")
Thanks Davide,
It does appear that /: needs a dyad with an initial value to the left:
q)3 {x,y}/:(0 1;2 3;4 5)
3 0 1
3 2 3
3 4 5
[as the reference states]
it also appears to apply to other adverbs:
q)0+/1 2 3
6
so (NtAe) is a q expression:
q)0{y\*y}'til 4
0 1 4 9
jack