let L1, L2 be non empty reflexive antisymmetric RelStr ; :: thesis: ( RelStr(# the carrier of L1,the InternalRel of L1 #) = RelStr(# the carrier of L2,the InternalRel of L2 #) & L1 is up-complete implies for x being Element of
for y being Element of st x = y & x is compact holds
y is compact )
assume A1: ( RelStr(# the carrier of L1,the InternalRel of L1 #) = RelStr(# the carrier of L2,the InternalRel of L2 #) & L1 is up-complete ) ; :: thesis: for x being Element of
for y being Element of st x = y & x is compact holds
y is compact
let x be Element of ; :: thesis: for y being Element of st x = y & x is compact holds
y is compact
let y be Element of ; :: thesis: ( x = y & x is compact implies y is compact )
assume that
A2: x = y and
A3: x is compact ; :: thesis: y is compact
x << x by A3, WAYBEL_3:def 2;
then y << y by A1, A2, Th8;
hence y is compact by WAYBEL_3:def 2; :: thesis: verum