[Groff] Depict symmetric difference in PIC

[btober]

I would like to know if anyone can help me depict symmetric difference of sets 
in PIC.

Searching the archives, I found some previous postings about basic Venn 
diagrams,
and I have developed graphics for set union, intersection, and relative 
complement, but I'm stuck on depicting the symmetric difference.

That is, given sets A, B, I want to depict the resulting set from

(A union B) - (A intersection B)

If A and B were depicted as overlapping circles, the symmetric difference would 
be the two outer crescents.

Or alternatively, as 

(A - B) union (B -A)

Here is (A - B)

.po 0.35i
.PS
move 
{A: circle invisible fill rad 1.2}
move right 0.5
B: circle invisible fill 0 rad 1.4
.ps +10
move to A
move up 0.8
move left 0.35
"milk"
move left 0.2
move down  0.3
"juice"
move left .35
move down  0.35
"jam"
.PE


and here is (B - A)

.po 0.35i
.PS
move 
{move right 0.5
B: circle invisible fill rad 1.4
}     
{A: circle invisible fill 0 rad 1.2}
.ps +10
move to B
move up 1
move right 0.3
"butter"
move down 0.35
move right .2
"bacon"
move down 0.35
move right 0.15
"sausage"
move down 0.35
"ham"
.PE