In Applescript, if you declare a handler using "with" labeled parameters, local variables get the values of the arguments and the parameters themselves are undefined. For example:

on bam of thing with frst and scnd
    local eat_frst
    return {thing: thing, frst:frst, scnd:scnd} -- this line throws an error
end bam
bam of "bug-AWWK!" with frst without scnd 

results in an error message that "scnd" isn't defined in the second line of bam. thing and frst are both defined, getting the arguments passed in the call to bam. Why is this happening? Why is scnd undefined?

Note: I know that declaring variables as "local" within a handler is unnecessary. It's done in the examples for illustrative purposes.