theorem Th117:
for
D being non
empty set for
A being
BinOp of
D for
d1,
d2 being
Element of
D for
f being
FinSequence of
D st
A is
having_a_unity &
A is
associative &
A is
commutative &
A is
having_an_inverseOp holds
for
F being non
empty finite set st
union F c= dom f holds
for
F1,
F2 being
finite set st
F1 = UNION (
F,
(bool {((len f) + 1)})) &
F2 = UNION (
F,
(bool {((len f) + 1),((len f) + 2)})) holds
ex
E1,
E2 being
Enumeration of
F1 ex
E being
Enumeration of
F2 st
A "**" ((SignGenOp (((f ^ <*d1*>) ^ <*d2*>),A,F2)) * E) = (A "**" ((SignGenOp ((f ^ <*(A . (d1,d2))*>),A,F1)) * E1)) ^ (A "**" ((SignGenOp ((f ^ <*(A . (((the_inverseOp_wrt A) . d1),d2))*>),A,F1)) * E2))