Roland Rau <roland.rproject <at> gmail.com> writes: > > does this do what you want? > > overlap <- function(a,b,c,d) { > all(c:d %in% a:b) > } > overlap(1,5,3,4) > overlap(1,2,3,4) Do you really want this to be discrete? How about overlap <- function(a,b,c,d) { a<c && b>d } (although this assumes that a<b and c<d ...)