[R] an operator for "contains"

[Mike R]

k = c(1:9)
if( length( which(k==3) ) ){ print("contained") }else{ print("not contained") }

is therre a simple way to test if a vector/list contains a particular value?

for example an operator, along the lines of: ==

more generally, is the a documentaion page that lists/describes all
such operators?

lastly, if you didn't know the answer to my question, how would you have
gone about searching for an answer?  I tried RSiteSearch() using various
terms, and I opened  R-2.1.0/library/base/html/00Index.html and searched
for various terms.

TIA

======================
platform i686-pc-linux-gnu
arch     i686             
os       linux-gnu        
system   i686, linux-gnu  
status                    
major    2                
minor    1.0              
year     2005             
month    04               
day      18               
language R