R help - Apr 2016 - could not find function in mempry inside foreach loop

I'm trying to use foreach function to do multicore computing in R.

A <-function(....) {
    foreach(i=1:10) %dopar% {
    B()
    }}

then I call function A in the console. The problem is I'm calling a
function  ipredictMatrix inside B that is defined in another script file
which I source.However I get the following error:

Error in FUN(train_adjmt, iter = missedmat[i, 1], iter2 = missedmat[i,  :
  task 1 failed - "?????'predictMatrix'"

Then  I tried to put predictMatrix in the list of export argument of foreach
: .export=c("predictMatrix"). However I get the following error:

Warning message:
In e$fun(obj, substitute(ex), parent.frame(), e$data) :
  already exporting variable(s): predictMatrix

Why  can't R find this defined function? How to solve this problem?
Futermore ,R-version I am using is "3.2.3",and my computer is running
on
windows.

Thanks,
Alice

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