[Rd] setdiff bizarre

[Wacek Kusnierczyk]

Stavros Macrakis wrote:
>
>      '1:3' %in% data.frame(a=2:4,b=1:3)  # TRUE
>   

utterly weird.  so what would x have to be so that

    x %in% data.frame('a')
    # TRUE

hint: 

    '1' %in% data.frame(1)
    # TRUE

vQ