How to detect that a vector is subset of specific vector?

Question

I have two vectors (sets) like this:

first<-c(1,2,3,4,5)
second<-c(2,4,5)

how can I detect that whether second is subset

Answer 1

Here's another

setequal(intersect(first, second), second)
## [1] TRUE

Or

all(is.element(second, first))
## [1] TRUE