theorem
for
X being
set for
L1,
L2 being
List of
X for
O1,
O2 being
Operation of
X st
L1 c= L2 &
O1 c= O2 holds
L1 | O1 c= L2 | O2
theorem Th29:
for
X being
set for
O1,
O2 being
Operation of
X st ( for
x being
Element of
X holds
x . O1 = x . O2 ) holds
O1 = O2
theorem Th30:
for
X being
set for
O1,
O2 being
Operation of
X st ( for
L being
List of
X holds
L | O1 = L | O2 ) holds
O1 = O2
definition
let X be
set ;
let O be
Operation of
X;
existence
ex b1 being Operation of X st
for L being List of X holds L | b1 = union { (IFEQ ((x . O),{},{x},{})) where x is Element of X : x in L }
uniqueness
for b1, b2 being Operation of X st ( for L being List of X holds L | b1 = union { (IFEQ ((x . O),{},{x},{})) where x is Element of X : x in L } ) & ( for L being List of X holds L | b2 = union { (IFEQ ((x . O),{},{x},{})) where x is Element of X : x in L } ) holds
b1 = b2
end;