Every operation is function

Every operator in R, such as + is a function. Therefore, you can have:

> `+`(8,5)
[1] 13

> mapply(`*`, 1:4, 4:1)
[1] 4 6 6 4

Also, you can define your custom operator, which must be wrapped by %:

> `%@@%` <- function(a,b){ c(a,b) }
> 4 %@@% 7
[1] 4 7

And you can use operator with %>% operator in magrittr package (which is usually imported when loading dplyr package):

> 5 %>% `+`(4) %>% `*`(3)
[1] 27