[darcs-users] question mergers, revisited
Mirian Crzig Lennox
list-darcs-users at cosmic.com
Mon Jan 19 17:49:07 UTC 2004
Back in December, I posted that I had been having some difficulty
unwinding a particular hypothetical merger:
M(M(A,B),M(M(C,D),E))
I began by unwinding the two halves,
C
A M(C,D)
M(A,B) M(M(C,D),E)
then got stuck trying to reconcile patch A with M(C,D). After staring
at the problem for on three weeks, this is what I've come up with:
* Since none of the mergers in either column involves A with C or D,
we may assume that AC' <=> CA' and AD' <=> DA' are valid
commutations.
* By definition, a merger comprises parallel patches; thus M(P1,P2) is
semantically equivalent to M(P2,P1) regardless of context.
Furthermore, for any simple patch P3,
if P1P3 <=> P3'P1' and P2P3 <=> P3'P2' then M(P1,P2)P3 <=> P3'M(P1'P2')
Consequently, my full unwinding works out to:
C'
M(C'D')
A
M(A,B)
M(M(A,B),M(M(C,D),E))
Where C' and D' are C and D respectively commuted with A.
Is this correct?
cheers,
Mirian
More information about the darcs-users
mailing list