# System Variable LR

(Redirected from System Variable DQ)

# ⎕LR - Left/Right Direction Choice

 Z←⎕LR returns the current value of the Left/Right Direction Choice.
Z is a character scalar containing the current value of ⎕LR. This is the value used by certain primitive functions when a choice of Left vs.Right is needed such as when dividing non-commutative numbers or when returning the matrix representation of an Octonion number — the value is either 'l' or 'r'.

 ⎕LR←'l' sets the Left/Right Direction Choice to Left ⎕LR←'r' sets the Left/Right Direction Choice to Right
```      a←<⍳4
b←<⌽⍳4
⎕LR←'l' ⋄ a÷b
0.66667i0j0.66667k0.33333
⎕LR←'r' ⋄ a÷b
0.66667i0.33333j0k0.66667```

This setting may be localized to an individual function via the Variant operator:

```      a÷⍠'l' b
0.66667i0j0.66667k0.33333
a÷⍠'r' b
0.66667i0.33333j0k0.66667
```
System Variables (A value may be assigned to these except for ⎕DM)
ALX CT DM DT ELX FC FEATURE FPC IC IO
LR LX PP PR PW RL SA WSID
Niladic System Functions (a value cannot be assigned to these)
A AV EM ET LC NNAMES NNUMS SI SYSID SYSVER
T TC TCBEL TCBS TCESC TCFF TCHT TCLF TCNL TCNUL
TS WA
Monadic or dyadic system functions (a value cannot be assigned to these)
AT CR DC DFT DL DR EA EC ERROR ES
EX FMT FX MF NAPPEND NC NCREATE NERASE NINFO NL
NLOCK NREAD NRENAME NREPLACE NRESIZE NSIZE NTIE NUNTIE STOP TF
TRACE UCS VR
Note that quad functions and variables (except for the ⎕A family of functions) are case insensitive