mysteriously persistent generic definition

Originally I made a function yearStop that took an argument "object".  I
made a generic, but later changed the argument to "x".  R keeps
resurrecting the old definition.  Could anyone explain what is going on,
or how to fix it?  Note particularly the end of the transcript below: I
remove the generic, verify that the symbol is undefined, make a new
function, and then make a generic.  But the generic does not use the
argument of the new function definition.

<quote>

args(yearStop)

function (obj) 
NULL

yearStop <- function(x) x at yearStop
args(yearStop)

function (x) 
NULL

setGeneric("yearStop")

[1] "yearStop"

args(yearStop)

function (obj) 
NULL

removeGeneric("yearStop")

[1] TRUE

args(yearStop)

Error in args(yearStop) : object "yearStop" not found

yearStop <- function(x) x at yearStop
setGeneric("yearStop")

[1] "yearStop"

args(yearStop)

function (obj) 
NULL
</quote>

R 2.7.1.  I originally read the definitions in from a file with ^c^l in

ESS; however, I typed the commands above by hand.

Thanks.
Ross Boylan

foo <- function(obj) {return(3);}
setGeneric("foo")

removeGeneric("foo")

foo <- function(x) {return(4);}
args(foo)

setGeneric("foo")

args(foo)

setMethod("foo", signature(x="numeric"), function(x) {return(x+4);})

Here's a self-contained example of the problem:

foo <- function(obj) {return(3);}
setGeneric("foo")

[1] "foo"

removeGeneric("foo")

[1] TRUE

foo <- function(x) {return(4);}
args(foo)

function (x) 
NULL

setGeneric("foo")

[1] "foo"

args(foo)

function (obj) 
NULL

R 2.7.1.  I get the same behavior whether or not I use ESS.

The reason this is more than a theoretical problem:

setMethod("foo", signature(x="numeric"), function(x) {return(x+4);})

Error in match.call(fun, fcall) : unused argument(s) (x = "numeric")

Ross 

Here's a self-contained example of the problem:

foo <- function(obj) {return(3);}
setGeneric("foo")

[1] "foo"

removeGeneric("foo")

[1] TRUE

foo <- function(x) {return(4);}
args(foo)

function (x) 
NULL

setGeneric("foo")

[1] "foo"

args(foo)

function (obj) 
NULL

R 2.7.1.  I get the same behavior whether or not I use ESS.

The reason this is more than a theoretical problem:

setMethod("foo", signature(x="numeric"), function(x) {return(x+4);})

Error in match.call(fun, fcall) : unused argument(s) (x = "numeric")