▁is ▁contained ▁in ▁ ▁the ▁complexity ▁class ▁P ▁of ▁problems ▁sol v able ▁in ▁determin istic ▁polynomial ▁time . ▁Thus ▁L   ⊆   NL   ⊆   P . ▁The ▁inclusion ▁of ▁L ▁into ▁P ▁can ▁also ▁be ▁proved ▁more ▁directly : ▁a ▁dec ider ▁using ▁O ( log   n ) ▁space ▁cannot ▁use ▁more ▁than ▁ 2 O ( log   n )   =   n O ( 1 ) ▁time , ▁because ▁this ▁is ▁the ▁total ▁number ▁of ▁possible ▁configurations . ▁ ▁L ▁further ▁rel ates ▁to ▁the ▁class ▁NC ▁in ▁the ▁following ▁way : ▁NC 1   ⊆   L   ⊆   NL   ⊆   NC 2 . ▁In ▁words , ▁given ▁a ▁parallel ▁computer ▁C ▁with ▁a ▁polynomial ▁number ▁O ( n k ) ▁of ▁process ors ▁for ▁some ▁constant ▁k , ▁any ▁problem ▁that ▁can ▁be ▁solved ▁on ▁C ▁in ▁O ( log   n ) ▁time ▁is ▁in ▁L , ▁and ▁any ▁problem ▁in ▁L ▁can ▁be ▁solved ▁in ▁O ( log 2   n ) ▁time ▁on ▁C . ▁ ▁Import ant ▁open ▁problems ▁include ▁whether ▁L   =   P , ▁and ▁whether ▁L   =   NL . ▁ ▁The ▁related ▁class ▁of ▁function ▁problems ▁is ▁F L . ▁ ▁F L ▁is ▁often ▁used ▁to ▁define ▁log space ▁redu ctions . ▁ ▁Add itional ▁properties ▁L ▁is ▁low ▁for ▁itself , ▁because ▁it ▁can ▁simulate ▁log - space ▁oracle ▁queries ▁( rough ly ▁speaking , ▁" function ▁calls